BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Sabre//Sabre VObject 4.5.8//EN CALSCALE:GREGORIAN BEGIN:VTIMEZONE TZID:Europe/Zurich X-LIC-LOCATION:Europe/Zurich TZURL:http://tzurl.org/zoneinfo/Europe/Zurich BEGIN:DAYLIGHT TZOFFSETFROM:+0100 TZOFFSETTO:+0200 TZNAME:CEST DTSTART:19810329T020000 RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:+0200 TZOFFSETTO:+0100 TZNAME:CET DTSTART:19961027T030000 RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU END:STANDARD END:VTIMEZONE BEGIN:VEVENT UID:news1904@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20251006T093903 DTSTART;TZID=Europe/Zurich:20251030T161500 SUMMARY:Doktoratskolloquium Mathematik: Ramon Locher DESCRIPTION:Critical and near-critical level-set percolation of the Gaussia n free field on regular trees X-ALT-DESC:Critical and near-critical level-set percolation of the Gaussian free field on regular trees END:VEVENT BEGIN:VEVENT UID:news1909@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20250925T084214 DTSTART;TZID=Europe/Zurich:20251023T161500 SUMMARY:Doktoratskolloquium Mathematik: Carina Santos DESCRIPTION:SPACE-TIME ADAPTIVE FINITE ELEMENT METHODS WITH EXPLICIT TIME I NTEGRATION FOR THE WAVE EQUATION X-ALT-DESC:SPACE-TIME ADAPTIVE FINITE ELEMENT METHODS WITH EXPLICIT TIME IN TEGRATION FOR THE WAVE EQUATION END:VEVENT BEGIN:VEVENT UID:news1895@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20250715T133629 DTSTART;TZID=Europe/Zurich:20251016T150000 SUMMARY:[Nicht öffentlich] SciLib Forum 2025: AI meets Scientific Writing DTEND;TZID=Europe/Zurich:20250716T200000 END:VEVENT BEGIN:VEVENT UID:news1849@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20250605T095044 DTSTART;TZID=Europe/Zurich:20250612T161500 SUMMARY:Doktoratskolloquium Mathematik: Marco Inversi DESCRIPTION:Der Vortrag ist universitätsöffentlich.\\r\\nhttps://unibas.z oom.us/j/61649075342?pwd=INb8xMeiAt1aEJCqyiXGWhE2m8l7HY.1 [https://unibas. zoom.us/j/61649075342?pwd=INb8xMeiAt1aEJCqyiXGWhE2m8l7HY.1] \\r\\nID meeti ng : 616 4907 5342\\r\\nPasscode: 182300 X-ALT-DESC:

Der Vortrag ist universitätsöffentlich.

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h ttps://unibas.zoom.us/j/61649075342?pwd=INb8xMeiAt1aEJCqyiXGWhE2m8l7HY.1

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ID meeting : 616 4907 5342

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Passcode: 182300

END:VEVENT BEGIN:VEVENT UID:news1779@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20250219T094048 DTSTART;TZID=Europe/Zurich:20250227T161500 SUMMARY:Perlen-Kolloquium: Prof. Mathias Drton (Technical University Munich ) DESCRIPTION:The ultimate aim of many data analyses is to infer cause-effect relationships between random variables of interest. While much of the ava ilable methodology for addressing causal questions relies on structural ca usal models\, these models are best suited for systems without feedback lo ops. Extensions to accommodate feedback have been proposed but often resul t in models that are challenging to interpret.\\r\\nIn this talk\, we pres ent an alternative approach to structural causal modeling: graphical conti nuous Lyapunov models. This framework offers a novel perspective on modeli ng causally interpretable dependence structures in multivariate data by tr eating each independent observation as a one-time cross-sectional snapshot of an underlying temporal process. Specifically\, we focus on models base d on multivariate Ornstein-Uhlenbeck processes in equilibrium\, which yiel d Gaussian distributions where the continuous Lyapunov equation determines the covariance matrix. Within this framework\, each graphical model assum es a sparse drift matrix whose support is encoded by a directed graph.\\r\ \nWe will discuss initial results on the identifiability of sparse drift m atrices and explore methods for their regularized estimation\, highlightin g the potential as well as challenges in developing graphical continuous L yapunov models as an interpretable tool for causal analysis in systems wit h feedback loops. X-ALT-DESC:

The ultimate aim of many data analyses is to infer cause-effe ct relationships between random variables of interest. While much of the a vailable methodology for addressing causal questions relies on structural causal models\, these models are best suited for systems without feedback loops. Extensions to accommodate feedback have been proposed but often res ult in models that are challenging to interpret.

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In this talk\, we present an alternative approach to structural causal modeling: graphical continuous Lyapunov models. This framework offers a novel perspective on m odeling causally interpretable dependence structures in multivariate data by treating each independent observation as a one-time cross-sectional sna pshot of an underlying temporal process. Specifically\, we focus on models based on multivariate Ornstein-Uhlenbeck processes in equilibrium\, which yield Gaussian distributions where the continuous Lyapunov equation deter mines the covariance matrix. Within this framework\, each graphical model assumes a sparse drift matrix whose support is encoded by a directed graph .

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We will discuss initial results on the identifiability of sparse drift matrices and explore methods for their regularized estimation\, hig hlighting the potential as well as challenges in developing graphical cont inuous Lyapunov models as an interpretable tool for causal analysis in sys tems with feedback loops.

END:VEVENT BEGIN:VEVENT UID:news1795@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20250218T093546 DTSTART;TZID=Europe/Zurich:20250220T161500 SUMMARY:Doktoratskolloquium Mathematik: Marta Dujella DESCRIPTION:Counting points of bounded height on abelian varieties defined over number fields is a well-studied problem in arithmetic geometry. A cla ssical result of Néron describes asymptotical behavior for this counting problem\, with dependence on the Mordell-Weil rank of the abelian variety. In this talk\, we'll present the problem of achieving uniform bounds in t his setting. Particularly\, we consider two special cases in which we are able to reach uniformity. In the first part\, we consider the one-dimensio nal case\, that of elliptic curves. X-ALT-DESC:

Counting points of bounded height on abelian varieties define d over number fields is a well-studied problem in arithmetic geometry. A c lassical result of Néron describes asymptotical behavior for this countin g problem\, with dependence on the Mordell-Weil rank of the abelian variet y. In this talk\, we'll present the problem of achieving uniform bounds in this setting. Particularly\, we consider two special cases in which we ar e able to reach uniformity. In the first part\, we consider the one-dimens ional case\, that of elliptic curves.

END:VEVENT BEGIN:VEVENT UID:news1723@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20240916T114921 DTSTART;TZID=Europe/Zurich:20241121T161500 SUMMARY:Perlenkolloquium: Prof. Dr. Joachim Rosenthal (UZH) DESCRIPTION:Public key cryptography has been at the center of modern crypto graphy.  It is not only used for the exchange of secret keys but also for the authentication of entities on the Internet\, for digital signatures a nd for the construction of digital currencies.\\r\\nUntil a few years ago most public key systems were based on the hardness of factoring integers o r on the hardness of the discrete logarithm problem in an elliptic curve.\ \r\\nWith the realization that a quantum computer would make many practica lly used public key cryptographic systems obsolete it became an important research topic to design public key systems which are expected to be secur e even if a powerful quantum computer would exist.\\r\\nThis new area of r esearch is called post-quantum cryptography and there has been in the last couple of years a lot of efforts to come up with new standards to be used in everyday applications.\\r\\nThe main part of the lecture will overview this recent development and will explain the underlying mathematical prob lems. X-ALT-DESC:

Public key cryptography has been at the center of modern cryp tography. \; It is not only used for the exchange of secret keys but a lso for the authentication of entities on the Internet\, for digital signa tures and for the construction of digital currencies.

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Until a few years ago most public key systems were based on the hardness of factoring integers or on the hardness of the discrete logarithm problem in an ellipt ic curve.

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With the realization that a quantum computer would make many practically used public key cryptographic systems obsolete it became an important research topic to design public key systems which are expecte d to be secure even if a powerful quantum computer would exist.

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Th is new area of research is called post-quantum cryptography and there has been in the last couple of years a lot of efforts to come up with new stan dards to be used in everyday applications.

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The main part of the le cture will overview this recent development and will explain the underlyin g mathematical problems.

END:VEVENT BEGIN:VEVENT UID:news1620@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20240326T111132 DTSTART;TZID=Europe/Zurich:20240411T161500 SUMMARY:Perlen-Kolloquium: Prof. Roman Shvydkoy (University of Illinois at Chicago) DESCRIPTION:Emergence is a phenomenon of formation of collective outcomes i n systems where communication between agents has local range. For a wide range of applications\, such as swarming behavior of animals or exchange o f opinions between individuals\, such outcomes result in a globally aligne d state or congregation of aligned clusters. The classical result of Cucke r and Smale states that alignment is unconditional in groups that facilita te global interactions with non-integrable radial tails. Proving a similar statement for purely local interactions is a challenging mathematical pro blem. There have been several programs of research directed  towards unde rstanding the emergent phenomena on micro\, kinetic\, and macro levels of description. In this talk we will mostly focus on the kinetic approach and demonstrate its connection with the classical problem of relaxation for non-perturbative data. X-ALT-DESC:

Emergence is a phenomenon of formation of collective outcomes in systems where communication between agents has local \;range. For a wide range of applications\, such as swarming behavior of animals or exc hange of opinions between individuals\, such outcomes result in a globally aligned state or congregation of aligned clusters. The classical result o f Cucker and Smale states that alignment is unconditional in groups that f acilitate global interactions with non-integrable radial tails. Proving a similar statement for purely local interactions is a challenging mathemati cal problem. There have been several programs of research directed \; towards understanding the emergent phenomena on micro\, kinetic\, and macr o levels of description. In this talk we will mostly focus on the kinetic approach and demonstrate \;its connection with the classical problem o f relaxation for non-perturbative data.

END:VEVENT BEGIN:VEVENT UID:news1584@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20231122T084257 DTSTART;TZID=Europe/Zurich:20240314T161500 SUMMARY:Perlen-Kolloquium: Prof. Jean-Pierre Eckmann (Universität Genf) DESCRIPTION:A cylinder will roll down an inclined plane in a straight line. A cone will wiggle along a circle on that plane and then will stop rollin g. We ask the inverse question: For which curves drawn on the inclined pla ne $\\real^2$ can one chisel a shape that will roll downhill following pre cisely this prescribed curve and its translationally repeated copies? Thi s is a nice\, and easy to understand problem\, but the solution is quite i nteresting. (Based on work mostly with Y. Sobolev and T. Tlusty. After a Nature paper\, Solid-body trajectoids shaped to roll along desired pathway s\, August 2023.) X-ALT-DESC:

A cylinder will roll down an inclined plane in a straight lin e. A cone will
wiggle along a circle on that plane and then will sto p rolling.
We ask the inverse question: For which curves drawn on th e inclined plane
$\\real^2$ can one chisel a shape that will roll do wnhill following precisely
this prescribed curve and its translation ally repeated copies?

This is a nice\, and easy to understand problem\, but the solution is quite
interesting.

(Base d on work mostly with Y. Sobolev and T. Tlusty. After a Nature paper\,
Solid-body trajectoids shaped to roll along desired pathways\, August 2 023.)

END:VEVENT BEGIN:VEVENT UID:news1590@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20231016T120449 DTSTART;TZID=Europe/Zurich:20231020T151500 SUMMARY:Doktoratskolloquium Mathematik: Gerold Schefer DESCRIPTION:Ih's conjecture and logarithmic equidistribution X-ALT-DESC:Ih's conjecture and logarithmic equidistribution END:VEVENT BEGIN:VEVENT UID:news1581@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20231005T110022 DTSTART;TZID=Europe/Zurich:20231012T161500 SUMMARY:Doktoratskolloquium Mathematik: Yannik Gleichmann DESCRIPTION:Adaptive Spectral Inversion for Inverse Medium Problems X-ALT-DESC:Adaptive Spectral Inversion for Inverse Medium Problems END:VEVENT BEGIN:VEVENT UID:news1563@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20230913T122018 DTSTART;TZID=Europe/Zurich:20230921T161500 SUMMARY:Habilitationsvorlesung von PD Dr. Immanuel van Santen DESCRIPTION:After introducing the relevant notions\, we will consider the c lassical setting of algebraic embeddings into Euclidean space.\\r\\nTherea fter\, we will focus on more general targets for algebraic embeddings\, ma inly linear algebraic groups. X-ALT-DESC:

After introducing the relevant notions\, we will consider the classical setting of algebraic embeddings into Euclidean space.

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T hereafter\, we will focus on more general targets for algebraic embeddings \, mainly linear algebraic groups.

\n\n END:VEVENT BEGIN:VEVENT UID:news1457@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20230309T105716 DTSTART;TZID=Europe/Zurich:20230427T161500 SUMMARY:Perlen-Kolloquium: Dr. Frank Bretz (Novartis) DESCRIPTION:We consider the problem of testing multiple null hypotheses\, w here a decision to reject or retain must be made for each one and embeddin g incorrect decisions into a real-life context may inflict different losse s. We argue that traditional methods controlling the Type I error rate may be too restrictive in this situation and that the standard familywise err or rate may not be appropriate. Using a decision-theoretic approach\, we d efine suitable loss functions for a given decision rule\, where incorrect decisions can be treated unequally by assigning different loss values. Tak ing expectation with respect to the sampling distribution of the data allo ws us to control the familywise expected loss instead of the conventional familywise error rate. Different loss functions can be adopted\, and we se arch for decision rules that satisfy certain optimality criteria within a broad class of decision rules for which the expected loss is bounded by a fixed threshold under any parameter configuration. We illustrate the metho ds with the problem of establishing efficacy of a new medicinal treatment in non-overlapping subgroups of patients. X-ALT-DESC:

We consider the problem of testing multiple null hypotheses\, where a decision to reject or retain must be made for each one and embedd ing incorrect decisions into a real-life context may inflict different los ses. We argue that traditional methods controlling the Type I error rate m ay be too restrictive in this situation and that the standard familywise e rror rate may not be appropriate. Using a decision-theoretic approach\, we define suitable loss functions for a given decision rule\, where incorrec t decisions can be treated unequally by assigning different loss values. T aking expectation with respect to the sampling distribution of the data al lows us to control the familywise expected loss instead of the conventiona l familywise error rate. Different loss functions can be adopted\, and we search for decision rules that satisfy certain optimality criteria within a broad class of decision rules for which the expected loss is bounded by a fixed threshold under any parameter configuration. We illustrate the met hods with the problem of establishing efficacy of a new medicinal treatmen t in non-overlapping subgroups of patients.

\n\n END:VEVENT BEGIN:VEVENT UID:news1459@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20230118T100937 DTSTART;TZID=Europe/Zurich:20230127T160000 SUMMARY:WMI Mathematics Kolloquium DESCRIPTION:For more information and the link to the event please visit the website of the Warwick Mathematics Institute (WMI). [https://warwick.ac.u k/fac/sci/maths/research/events/colloquium/2223/] X-ALT-DESC:

For more information and the link to the event please visit t he website of the Warwick Mathematics Institute (WMI).

END:VEVENT BEGIN:VEVENT UID:news1121@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20201111T091948 DTSTART;TZID=Europe/Zurich:20201126T160000 SUMMARY:Perlen-Kolloquium: Prof. Dr. Emil Wiedemann (Universität Ulm) DESCRIPTION:Convex integration is a technique\, or rather a broad range of techniques\, that originated in Nash's work on isometric embeddings of man ifolds in the 1950s. It serves to produce 'unexpected' solutions to variou s geometric or analytic problems with peculiar behaviour. Convex integrati on has become very trendy again in the past ten years or so\, when it turn ed out that it surprisingly applies to the fundamental equations of fluid mechanics\, including the Euler and Navier-Stokes systems. Since contempor ary applications\, however\, have become increasingly technical\, it is of ten not easy to grasp the fundamental mechanism. I will attempt to present this convex integration mechanism in a simple way\, and to discuss some a pplications to isometric embedding\, fluid dynamics\, and breakdown of the chain rule for functions of low regularity. X-ALT-DESC:

Convex integration is a technique\, or rather a broad range of techniques\, that originated in Nash's work on isometric embeddings of manifolds in the 1950s. It serves to produce 'unexpected' solutions to var ious geometric or analytic problems with peculiar behaviour. Convex integr ation has become very trendy again in the past ten years or so\, when it t urned out that it surprisingly applies to the fundamental equations of flu id mechanics\, including the Euler and Navier-Stokes systems. Since contem porary applications\, however\, have become increasingly technical\, it is often not easy to grasp the fundamental mechanism. I will attempt to pres ent this convex integration mechanism in a simple way\, and to discuss som e applications to isometric embedding\, fluid dynamics\, and breakdown of the chain rule for functions of low regularity.

END:VEVENT BEGIN:VEVENT UID:news997@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20200129T121251 DTSTART;TZID=Europe/Zurich:20200213T141500 SUMMARY:Verleihung des Ostrowski Preis 2019 DESCRIPTION:Die Zeremonie zu Ehren von Prof. Dr. Assaf Naor\, Empfänger de s Ostrowski Preis 2019\, wird am 13. Februar 2020 um 14:15 Uhr im Hörsaal -101 der Alten Universität stattfinden.\\r\\nBegrüssung:\\r\\nGianluca Crippa\, Departementsvorsteher\\r\\n\\r\\nA.M. Ostrowski und die Präsenta tion des Preises:\\r\\nHelmut Harbrecht\, Präsident der Ostrowski-Stiftun g\\r\\n\\r\\nLaudatio: \\r\\nTerence Tao\, University of California\, Los Angeles\\r\\n\\r\\nÜberreichung der Medaille der Ostrowski-Stiftung\\r\\n \\r\\nPreisvortrag durch den Preisträger Assaf Naor\\r\\n\\r\\nIm Anschlu ss an die Zeremonie wird ein Apéro offeriert. X-ALT-DESC:

Die Zeremonie zu Ehren von Prof. Dr. Assaf Naor\, Empfänger des Ostrowski Preis 2019\, wird am 13. Februar 2020 um 14:15 Uhr im Hörsa al -101 der Alten Universität stattfinden.

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Begrüssung:

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G ianluca Crippa\, Departementsvorsteher

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A.M. Ostrowski und die Pr äsentation des Preises:

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Helmut Harbrecht\, Präsident der Ostrows ki-Stiftung

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Laudatio:

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Terence Tao\, University of Calif ornia\, Los Angeles

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Überreichung der Medaille der Ostrowski-Sti ftung

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Preisvortrag durch den Preisträger Assaf Naor

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I m Anschluss an die Zeremonie wird ein Apéro offeriert.

END:VEVENT BEGIN:VEVENT UID:news999@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20200116T144001 DTSTART;TZID=Europe/Zurich:20200117T180000 SUMMARY:DBIS Forschungsgruppe bei der Basler Museumsnacht DESCRIPTION:Sie wollten sich schon immer einmal den Basler Münsterschatz a us unmittelbarer Nähe anschauen? Dann bietet die 20. Basler Museumsnacht [https://museumsnacht.ch/] am Freitag den 17. Januar 2020 eine gute Gelege nheit. Teile des digitalisierten Münsterschatzes werden im Virtuellen Mus eum der Forschungsgruppe Datenbanken und Informationssysteme (DBIS) [https ://dbis.dmi.unibas.ch/] der Universität Basel in der Barfüsserkirche zu bestaunen sein.  X-ALT-DESC:

Sie wollten sich schon immer einmal den Basler Münsterschatz aus unmittelbarer Nähe anschauen? Dann bietet die 20. Basler Museumsnacht am Freitag den 17. Januar 20 20 eine gute Gelegenheit. Teile des digitalisierten Münsterschatzes werde n im Virtuellen Museum der Fors chungsgruppe Datenbanken und Informationssysteme (DBIS) der Universit ät Basel in der Barfüsserkirche zu bestaunen sein. \;

DTEND;TZID=Europe/Zurich:20200118T020000 END:VEVENT BEGIN:VEVENT UID:news983@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20191204T100831 DTSTART;TZID=Europe/Zurich:20191212T161500 SUMMARY:Öffentliche Antrittsvorlesung von Prof. Dr. Pierre Le Boudec DESCRIPTION:Das Departement Mathematik und Informatik lädt Sie herzlich zu der Antrittsvorlesung von Prof. Dr. Pierre Le Boudec ein. Im Anschluss an die Vorlesung wird ein Apéro offeriert. X-ALT-DESC:

Das Departement Mathematik und Informatik lädt Sie herzlich zu der Antrittsvorlesung von Prof. Dr. Pierre Le Boudec ein. Im Anschluss an die Vorlesung wird ein Apéro offeriert.

DTEND;TZID=Europe/Zurich:20191212T171500 END:VEVENT BEGIN:VEVENT UID:news918@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20191030T110800 DTSTART;TZID=Europe/Zurich:20191125T161500 SUMMARY:Doktoratskolloquium Mathematik: Gabriel Dill DESCRIPTION:Unlikely Intersections with Isogeny Orbits X-ALT-DESC:Unlikely Intersections with Isogeny Orbits END:VEVENT BEGIN:VEVENT UID:news848@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190903T091658 DTSTART;TZID=Europe/Zurich:20191122T151500 SUMMARY:Perlen-Kolloquium: PD Dr. Andreas Verdun (Universität Bern) DESCRIPTION:Der Vortrag findet als gemeinsame Veranstaltung mit dem Depart ement Physik im Rahmen des Physik-Kolloquiums statt\, gefolgt von der Vern issage des Werkbandes II/26 der Opera Omnia von Leonhard Euler und einem A péro. \\r\\nDetails zum Anlass finden sich auf der Webseite des Departeme nts Physik [https://www.physik.unibas.ch/aktuell/seminars-colloquia/events -details/events/486-joint-colloquium-of-the-department-of-physics-and-the- department-of-mathematics-and-computer-sc.html]. X-ALT-DESC:Der Vortrag findet als gemeinsame Veranstaltung mit dem Departe ment Physik im Rahmen des Physik-Kolloquiums statt\, gefolgt von der Verni ssage des Werkbandes II/26 der Opera Omnia von Leonhard Euler und einem Ap éro. \nDetails zum Anlass finden sich auf der Webseite d es Departements Physik. END:VEVENT BEGIN:VEVENT UID:news916@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20191107T090529 DTSTART;TZID=Europe/Zurich:20191121T161500 SUMMARY:Doktoratskolloquium Mathematik: Silvia Ligabue DESCRIPTION:Der Vortrag ist universitätsöffentlich. X-ALT-DESC:

Der Vortrag ist universitätsöffentlich.

END:VEVENT BEGIN:VEVENT UID:news910@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20191030T140405 DTSTART;TZID=Europe/Zurich:20191114T161500 SUMMARY:Perlen-Kolloquium: Prof. Dr. Jürgen Hausen (Universität Tübingen ) DESCRIPTION:We begin with a short introduction to the theory of toric varie ties\, that means\, equivariant embeddings of the algebraic torus (k✲)n. Then we indicate how the methods of toric geometry can be extended to mor e general torus actions. As an application\, we discuss recent classificat ion results for Fano varieties.\\r\\nFlyer [t3://file?uid=2017] X-ALT-DESC:

We begin with a short introduction to the theory of toric var ieties\, that means\, equivariant embeddings of the algebraic torus (k✲) n. Then we indicate how the methods of toric geometry can be ex tended to more general torus actions. As an application\, we discuss recen t classification results for Fano varieties.

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Flyer

END:VEVENT BEGIN:VEVENT UID:news914@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190903T092752 DTSTART;TZID=Europe/Zurich:20191017T161500 SUMMARY:Doktoratskolloquium Mathematik: Jet Hoe Tang DESCRIPTION:Der Vortrag ist universitätsöffentlich. X-ALT-DESC:Der Vortrag ist universitätsöffentlich. END:VEVENT BEGIN:VEVENT UID:news903@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190910T145746 DTSTART;TZID=Europe/Zurich:20190918T100000 SUMMARY:Doktoratskolloquium Mathematik: Christine Bürli DESCRIPTION:Der Vortrag ist universitätsöffentlich. X-ALT-DESC: Der Vortrag ist universitätsöffentlich. END:VEVENT BEGIN:VEVENT UID:news899@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190624T131930 DTSTART;TZID=Europe/Zurich:20190626T150000 SUMMARY:Doktoratskolloquium Mathematik: Lars Bugiera DESCRIPTION:Der Vortrag ist universitätsöffentlich. X-ALT-DESC: Der Vortrag ist universitätsöffentlich. END:VEVENT BEGIN:VEVENT UID:news764@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190212T104547 DTSTART;VALUE=DATE:20190301 SUMMARY:Doktoratskolloquium Mathematik: Stefan Schmid DTEND;VALUE=DATE:20190228 END:VEVENT BEGIN:VEVENT UID:news303@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20181113T173748 DTSTART;TZID=Europe/Zurich:20181025T161500 SUMMARY:Perlen-Kolloquium: Dr. Jitao David Zhang (F. Hoffmann-La Roche AG\, Basel) DESCRIPTION:Mathematics is integral to the interdisciplinary research that drives modern drug discovery. The talk will walk the audience through basi c principles and selected applications of computational biology and bioinf ormatics\, a branch of applied mathematics\, in drug discovery\, It is hop ed that the principles\, examples\, and unsolved challenges discussed duri ng the talk can initiate an exchange between researchers from different fi elds\, and inspire future interdisciplinary efforts in disease understandi ng and drug discovery.\\r\\nJitao David Zhang was a Marie-Curie Fellow at European Bioinformatics Institute (2007-2008) and an International PhD Pro gramm Fellow at German Cancer Research Center (2008-2011). He obtained the doctorate degree in computational biology and biostatistics in 2011 and i n that year joined Pharma Research and Early Development (pRED)\, the rese arch unit of F. Hoffmann-La Roche AG in Basel\, Switzerland. He supports e arly drug-discovery projects\, develops algorithms and software for data a nalysis and interpretation\, and collaborates to devise new technologies a nd platforms. His research interests include biological data modelling and integration\, biological network analysis\, molecular phenotyping\, and a pplied machine learning in disease understanding and preclinical drug disc overy.\\r\\nSlides [t3://file?uid=1194] X-ALT-DESC: Mathematics is integral to the interdisciplinary research that drives modern drug discovery. The talk will walk the audience through basi c principles and selected applications of computational biology and bioinf ormatics\, a branch of applied mathematics\, in drug discovery\, It is hop ed that the principles\, examples\, and unsolved challenges discussed duri ng the talk can initiate an exchange between researchers from different fi elds\, and inspire future interdisciplinary efforts in disease understandi ng and drug discovery.\nJitao David Zhang was a Marie-Curie Fellow at Euro pean Bioinformatics Institute (2007-2008) and an International PhD Program m Fellow at German Cancer Research Center (2008-2011). He obtained the doc torate degree in computational biology and biostatistics in 2011 and in th at year joined Pharma Research and Early Development (pRED)\, the research unit of F. Hoffmann-La Roche AG in Basel\, Switzerland. He supports early drug-discovery projects\, develops algorithms and software for data analy sis and interpretation\, and collaborates to devise new technologies and p latforms. His research interests include biological data modelling and int egration\, biological network analysis\, molecular phenotyping\, and appli ed machine learning in disease understanding and preclinical drug discover y.\nSlides END:VEVENT BEGIN:VEVENT UID:news302@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20181113T164032 DTSTART;TZID=Europe/Zurich:20181004T161500 SUMMARY:Perlen-Kolloquium: Prof. Dr. Thomas Sonar (Technische Universität Braunschweig) DESCRIPTION:Der Prioritätsstreit um die Erfindung der Differential- und In tegralrechnung zwischen Leibniz und Newton nahm wesentlich Fahrt auf\, als Johann Bernoulli sich auf Leibniz'scher Seite\, und John Keill sich auf N ewtons Seite einschalteten. Im Vortrag berichten wir von diesem Verlauf de s Streits\, in dem Johann Bernoulli eine nicht immer rühmliche Rolle spie lte. X-ALT-DESC: Der Prioritätsstreit um die Erfindung der Differential- und In tegralrechnung zwischen Leibniz und Newton nahm wesentlich Fahrt auf\, als Johann Bernoulli sich auf Leibniz'scher Seite\, und John Keill sich auf N ewtons Seite einschalteten. Im Vortrag berichten wir von diesem Verlauf de s Streits\, in dem Johann Bernoulli eine nicht immer rühmliche Rolle spie lte. END:VEVENT BEGIN:VEVENT UID:news197@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20181113T164044 DTSTART;VALUE=DATE:20180920 SUMMARY:Doktoratskolloquium Mathematik: Mattias Hemmig END:VEVENT BEGIN:VEVENT UID:news200@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190212T101415 DTSTART;TZID=Europe/Zurich:20180621T161500 SUMMARY:Doktoratskolloquium Mathematik: Linda Frey END:VEVENT BEGIN:VEVENT UID:news196@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20181113T174040 DTSTART;TZID=Europe/Zurich:20180601T173000 SUMMARY:Perlen-Kolloquium: Maryna Viazovska (EPFL) DESCRIPTION:In this talk we will speak about packing problems in multidimen sional spaces. We will give an overview of this interesting class of mathe matical questions and recent progress in the area.  Also we will explain the importance of good packing configurations in applications such as inte rnet\, telecommunication\, and data storage.\\r\\nThe talk is part of the annual meeting 2018 of the Swiss Mathematical Society. X-ALT-DESC:\nIn this talk we will speak about packing problems in multidime nsional spaces. We will give an overview of this interesting class of math ematical questions and recent progress in the area. \; Also we will ex plain the importance of good packing configurations in applications such a s internet\, telecommunication\, and data storage.\nThe talk is part of th e annual meeting 2018 of the Swiss Mathematical Society. DTEND;TZID=Europe/Zurich:20180601T183000 END:VEVENT BEGIN:VEVENT UID:news195@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20180920T141100 DTSTART;TZID=Europe/Zurich:20180517T161500 SUMMARY:Öffentliche Habilitationsvorlesung von PD Dr. Jung-Kyu Canci: Dyna mical systems with a view toward arithmetic DESCRIPTION:A dynamical system is essentially the repeated iteration of an action.The study of dynamical systems has a long history. Many people cons ider Henri Poincaré as the founder (at the end of the 19th century) of th e modern theory of dynamical systems. Further important contributions at t he beginning of the 20th are due to George David Birkhoff\, Gaston Julia a nd Pierre Fatou.In the talk we will discuss some aspects of the theory of dynamical systems with a view toward arithmetic. As an example we will sho w that Birkhoff's multiple recurrence Theorem can be used to provide an al ternative proof of van der Waerden's Theorem on arithmetic progressions. W e will also show that Julia sets are useful to understand the dynamic give n by a rational function. X-ALT-DESC: A dynamical system is essentially the repeated iteration of an action.

The study of dynamical systems has a long history. Many people consider Henri Poincaré as the founder (at the end of the 19th ce ntury) of the modern theory of dynamical systems. Further important contri butions at the beginning of the 20th are due to George David Birkhoff\, Ga ston Julia and Pierre Fatou.

In the talk we will discuss some a spects of the theory of dynamical systems with a view toward arithmetic. A s an example we will show that Birkhoff's multiple recurrence Theorem can be used to provide an alternative proof of van der Waerden's Theorem on ar ithmetic progressions. We will also show that Julia sets are useful to und erstand the dynamic given by a rational function. DTEND;TZID=Europe/Zurich:20180517T171500 END:VEVENT BEGIN:VEVENT UID:news188@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20180920T141120 DTSTART;TZID=Europe/Zurich:20180315T161500 SUMMARY:Perlen-Kolloquium: Camillo De Lellis DESCRIPTION:The Plateau problem\, named by Henry Lebesgue after the Belgian physicist\, consists in finding the surface of least area which spans a g iven contour. In order to tackle such question\, generations of mathematic ians have investigated the very fundamental notions of "surface"\, "bounda ry" and "area"\, proposing a variety of dierent theories. In this talk I w ill give a brief exposition of the so-called theory of currents\, introduc ed by Federer and Fleming in the 60es after the pioneering work of De Gior gi in the case of hypersurfaces. I will then discuss an open question rela ting the shapes of the contour and that of the minimizer\, posed by Almgre n in the early eighties and recently solved in a joint work with Guido de Philippis\, Jonas Hirsch and Annalisa Massaccesi. \\r\\nFlyer [t3://file?u id=676] X-ALT-DESC: The Plateau problem\, named by Henry Lebesgue after the Belgian physicist\, consists in finding the surface of least area which spans a g iven contour. In order to tackle such question\, generations of mathematic ians have investigated the very fundamental notions of "\;surface" \;\, "\;boundary"\; and "\;area"\;\, proposing a variety o f di erent theories. In this talk I will give a brief exposition of the so -called theory of currents\, introduced by Federer and Fleming in the 60es after the pioneering work of De Giorgi in the case of hypersurfaces. I wi ll then discuss an open question relating the shapes of the contour and th at of the minimizer\, posed by Almgren in the early eighties and recently solved in a joint work with Guido de Philippis\, Jonas Hirsch and Annalisa Massaccesi. \nFlyer DTEND;TZID=Europe/Zurich:20180315T180000 END:VEVENT BEGIN:VEVENT UID:news526@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190106T231907 DTSTART;TZID=Europe/Zurich:20170929T161500 SUMMARY:Doktorkolloquium Mathematik: Dominik Himmelsbach DTEND;TZID=Europe/Zurich:20170929T173000 END:VEVENT BEGIN:VEVENT UID:news529@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T072540 DTSTART;TZID=Europe/Zurich:20170928T161500 SUMMARY:Doktorkolloquium Mathematik: Christian Urech DTEND;TZID=Europe/Zurich:20170928T171500 END:VEVENT BEGIN:VEVENT UID:news530@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T072958 DTSTART;TZID=Europe/Zurich:20170922T161500 SUMMARY:Doktorkolloquium Mathematik: Jürgen Dölz DTEND;TZID=Europe/Zurich:20170922T171500 END:VEVENT BEGIN:VEVENT UID:news531@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T072940 DTSTART;TZID=Europe/Zurich:20170518T161500 SUMMARY:Doktorkolloquium Mathematik: Ali Hyder DTEND;TZID=Europe/Zurich:20170518T171500 END:VEVENT BEGIN:VEVENT UID:news532@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T073353 DTSTART;TZID=Europe/Zurich:20170508T161500 SUMMARY:Doktorkolloquium Mathematik: Stefano Iula DTEND;TZID=Europe/Zurich:20170508T171500 END:VEVENT BEGIN:VEVENT UID:news533@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T073605 DTSTART;TZID=Europe/Zurich:20170505T161500 SUMMARY:Perlen-Kolloquium: Ivan Cheltsov DESCRIPTION:Pythagorean triples are given by rational parametrization of th e unit circle. Similarly\, all conics in the plane admits a similar para metrization. This is no longer the case for the curves of higher degrees.  \\r\\nFor example\, non-singular plane cubic curves (elliptic curves) c annot be rationally parametrized. In dimension one and two\, the problem of existence of such parametrization is completely solved.\\r\\nIn higher dimensions\, the picture is less clear. In this talk\, I will survey know results and open problems in this direction. X-ALT-DESC:Pythagorean triples are given by rational parametrization of the unit circle. Similarly\, all conics in the plane admits a similar param etrization. This is no longer the case for the curves of higher degrees.& nbsp\;\nFor example\, non-singular plane cubic curves (elliptic curves) c annot be rationally parametrized. In dimension one and two\, the problem of existence of such parametrization is completely solved.\nIn higher dim ensions\, the picture is less clear. In this talk\, I will survey know res ults and open problems in this direction. DTEND;TZID=Europe/Zurich:20170505T171500 END:VEVENT BEGIN:VEVENT UID:news534@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T075714 DTSTART;TZID=Europe/Zurich:20170420T161500 SUMMARY:Perlen-Kolloquium: Jürg Fröhlich (ETH Zürich) DESCRIPTION:This is a survey of effective dynamics in quantum theory and o f sources of irreversible behavior. After a shortrecap of properties of (r elative) entropy\, the following examples of irreversible behavior are di scussed:(1) The second law of thermodynamics is discussed within quantum statistical mechanics.(2) It is indicated how Brownian motion of a quantu m particle immersed in a heat bath can be derived from unitary quantum  dynamics of the total system.(3) Motion with friction is discussed in an example of Hamiltonian evolution equations for a particle moving through a dispersive wave medium.(4) It is sketched that and why quantum dynami cs is fundamentally irreversible. X-ALT-DESC: This is a survey of effective dynamics in quantum theory \; and of sources of irreversible behavior. After a short
recap of prope rties of (relative) entropy\, the following \;examples of irreversible behavior are discussed:
(1) The second law of thermodynamics is disc ussed within \;quantum statistical mechanics.
(2) It is indicate d how Brownian motion of a quantum particle \;immersed in a heat bath can be derived from unitary quantum \;dynamics of the total system.< br />(3) Motion with friction is discussed in an example of Hamiltonian&n bsp\;evolution equations for a particle moving through a dispersive \ ;wave medium.
(4) It is sketched that and why quantum dynamics is fun damentally \;irreversible. DTEND;TZID=Europe/Zurich:20170420T171500 END:VEVENT BEGIN:VEVENT UID:news536@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T080011 DTSTART;TZID=Europe/Zurich:20170302T161500 SUMMARY:Perlen-Kolloquium: Eitan Tadmor (University of Maryland & ETH-ITS) DESCRIPTION:Self-organization is observed in systems driven by the “social engagement”of agents with their local neighbors. Protot ypical models are found in opinion dynamics\, flocking\,self-organi zation of biological organisms\, and rendezvous in mobile networks.We disc uss the emergent behavior of such systems. Two natural questions arise in this context. The underlying issue of the first question is how di fferent rules of engagement influence the formation of clusters\, an d in particular\, the emergence of ‘consensus’. Different paradigms of emergence yield different patterns\, depending on the propagation o f connectivity of the underlying graphs of communication. The secon d question involves different descriptions of self-organized dynamics when the number of agents tends to infinity. It lends itself to “social hydr odynamics”\, driven by the corresponding tendency to move towards the lo cal means.We discuss the global regularity of social hydrodynamics for sub -critical initial configurations. X-ALT-DESC: Self-organization is observed in systems driven by the “social engagement”of agents with their local neighbors. Protot ypical models are found in opinion dynamics\, flocking\,self-organi zation of biological organisms\, and rendezvous in mobile networks.We disc uss the emergent behavior of such systems. Two natural questions arise in this context. The underlying issue of the first question is how di fferent rules of engagement influence the formation of clusters\, an d in particular\, the emergence of ‘consensus’. Different paradigms of emergence yield different patterns\, depending on the propagation o f connectivity of the underlying graphs of communication. The secon d question involves different descriptions of self-organized dynamics when the number of agents tends to infinity. It lends itself to “social hydr odynamics”\, driven by the corresponding tendency to move towards the lo cal means.We discuss the global regularity of social hydrodynamics for sub -critical initial configurations. DTEND;TZID=Europe/Zurich:20170302T171500 END:VEVENT BEGIN:VEVENT UID:news537@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T080302 DTSTART;TZID=Europe/Zurich:20161215T161500 SUMMARY:DMI Kolloquium: Florina Ciorba und Philipp Habegger DTEND;TZID=Europe/Zurich:20161215T171500 END:VEVENT BEGIN:VEVENT UID:news538@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T080518 DTSTART;TZID=Europe/Zurich:20161208T161500 SUMMARY:Perlen-Kolloquium: Laure Saint-Raymond (Université Paris VI – P. et M. Curie & École Normale Supérieure de Paris & Universität Zürich) DESCRIPTION:About irreversibility in rarefied gas dynamics X-ALT-DESC:About irreversibility in rarefied gas dynamics DTEND;TZID=Europe/Zurich:20161208T171500 END:VEVENT BEGIN:VEVENT UID:news539@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T081047 DTSTART;TZID=Europe/Zurich:20161201T171500 SUMMARY:DMI Kolloquium: Jérémy Blanc und Malte Helmert DTEND;TZID=Europe/Zurich:20161201T181500 END:VEVENT BEGIN:VEVENT UID:news540@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T081226 DTSTART;TZID=Europe/Zurich:20161124T161500 SUMMARY:Doktorkolloquium: Manuela Utzinger DESCRIPTION:An Adaptive Wavelet Method for the Solution of Boundary Integra l Equations in Three Dimensions X-ALT-DESC:An Adaptive Wavelet Method for the Solution of Boundary Integral Equations in Three Dimensions DTEND;TZID=Europe/Zurich:20161124T171500 END:VEVENT BEGIN:VEVENT UID:news541@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T081916 DTSTART;TZID=Europe/Zurich:20161121T161500 SUMMARY:Perlen-Kolloquium: Andreas Verdun (Bern) DESCRIPTION:Astronomica im Briefwechsel zwischen Leonhard Euler und Daniel Bernoulli X-ALT-DESC:Astronomica im Briefwechsel zwischen Leonhard Euler und Daniel B ernoulli DTEND;TZID=Europe/Zurich:20161121T171500 END:VEVENT BEGIN:VEVENT UID:news542@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T082030 DTSTART;TZID=Europe/Zurich:20161020T171500 SUMMARY:DMI Kolloquium: Marcus Grote und Thomas Vetter DTEND;TZID=Europe/Zurich:20161020T181500 END:VEVENT BEGIN:VEVENT UID:news543@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T082159 DTSTART;TZID=Europe/Zurich:20161006T161500 SUMMARY:Doktorkolloquium: Uri Nahum DTEND;TZID=Europe/Zurich:20161006T171500 END:VEVENT BEGIN:VEVENT UID:news544@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T082442 DTSTART;TZID=Europe/Zurich:20160912T170000 SUMMARY:KOLLOQUIUM: Hanspeter Kraft DTEND;TZID=Europe/Zurich:20160912T180000 END:VEVENT BEGIN:VEVENT UID:news545@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T082623 DTSTART;TZID=Europe/Zurich:20160908T161500 SUMMARY:Doktorkolloquium: Susanna Zimmermann DTEND;TZID=Europe/Zurich:20160908T171500 END:VEVENT BEGIN:VEVENT UID:news546@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T083307 DTSTART;TZID=Europe/Zurich:20160526T171500 SUMMARY:DMI Kolloquium: Helmut Harbrecht und Heiko Schuldt DTEND;TZID=Europe/Zurich:20160526T181500 END:VEVENT BEGIN:VEVENT UID:news547@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T084144 DTSTART;VALUE=DATE:20160420 SUMMARY:Symposium Wahrscheinlichkeitstheorie DESCRIPTION:Program [t3://file?uid=1445] X-ALT-DESC: Program DTEND;VALUE=DATE:20160421 END:VEVENT BEGIN:VEVENT UID:news548@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T100101 DTSTART;TZID=Europe/Zurich:20160407T161500 SUMMARY:Perlen-Kolloquium: Benoit Perthame (Paris 6) DESCRIPTION:Living systems are characterized by variability\; in the view of C. Darwin\, they are subject to constant evolution through th e three processes of population growth\, selection by nutrients limitation and mutations. Several mathematical theories have been proposed in order to describe the dynamics generated by the interaction between their enviro nment and the trait selection of the ‘fittest’. One can use stochastic individual based models\, dynamical systems\, game theory consider ing traits as strategies. From a populational point of view\, the pop ulation obeys an integro-partial-differential equation for the density num ber. We will give a self-contained mathematical model of such dyn amics and show that an asymptotic method allows us to formalize precisely the concepts of monomorphic or polymorphic population. Th en\, we can describe the evolution of the ‘fittest trait’ an d eventually compute various forms of branching points which represen t the cohabitation of two different populations. Recent developments conce rn non-proliferative advantages and lead to define the notion of ‘effect ivefitness’. The content of the colloquium is based on collaborations wi th G. Barles\, O. Diekmann\, M. Gauduchon\,S. Genieys\, P.-E. Jabin\, A. L orz\, S. Mirahimmi\, S. Mischler and P. E. Souganidis. X-ALT-DESC: Living systems are characterized by variability\; in the view of C. Darwin\, they are subject to constant evolution through th e three processes of population growth\, selection by nutrients limitation and mutations. Several mathematical theories have been proposed in order to describe the dynamics generated by the interaction between their enviro nment and the trait selection of the ‘fittest’. One can use stochastic individual based models\, dynamical systems\, game theory consider ing traits as strategies. From a populational point of view\, the pop ulation obeys an integro-partial-differential equation for the density num ber. We will give a self-contained mathematical model of such dyn amics and show that an asymptotic method allows us to formalize precisely the concepts of monomorphic or polymorphic population. Th en\, we can describe the evolution of the ‘fittest trait’ an d eventually compute various forms of branching points which represen t the cohabitation of two different populations. Recent developments conce rn non-proliferative advantages and lead to define the notion of ‘effect ivefitness’. The content of the colloquium is based on collaborations wi th G. Barles\, O. Diekmann\, M. Gauduchon\,S. Genieys\, P.-E. Jabin\, A. L orz\, S. Mirahimmi\, S. Mischler and P. E. Souganidis. DTEND;TZID=Europe/Zurich:20160407T171500 END:VEVENT BEGIN:VEVENT UID:news549@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T100205 DTSTART;TZID=Europe/Zurich:20160331T171500 SUMMARY:DMI Kolloquium: Gianluca Crippa und Volker Roth DTEND;TZID=Europe/Zurich:20160331T181500 END:VEVENT BEGIN:VEVENT UID:news550@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T100417 DTSTART;TZID=Europe/Zurich:20160303T171500 SUMMARY:DMI Kolloquium: Enno Lenzmann und Christian Tschudin DESCRIPTION:“Breaking Bad with Nonlocality“ & “Private Index Lookup – fetching data without revealing what is retrieved” X-ALT-DESC:“Breaking Bad with Nonlocality“ & “Private Index Lookup – fetching data without revealing what is retrieved” DTEND;TZID=Europe/Zurich:20160303T181500 END:VEVENT BEGIN:VEVENT UID:news551@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T100658 DTSTART;TZID=Europe/Zurich:20151210T161500 SUMMARY:Doktorkolloquium: Andriy Regeta DESCRIPTION:Groups of automorphisms of some affine varieties X-ALT-DESC:Groups of automorphisms of some affine varieties DTEND;TZID=Europe/Zurich:20151210T171500 END:VEVENT BEGIN:VEVENT UID:news552@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T100915 DTSTART;TZID=Europe/Zurich:20151015T161500 SUMMARY:Perlen-Kolloquium: Jonathan Pila (Oxford) DESCRIPTION:I will describe some diophantine results and conjectures\, from the Mordell conjecture of 1922 (theorem of Faltings) to the open and ver y general Zilber-Pink conjecture. I will describe a recent result and co njecture of similar flavour which are not formally consequences of the Zi lber-Pink conjecture. X-ALT-DESC: I will describe some diophantine results and conjectures\, from the Mordell conjecture of 1922 (theorem of Faltings) to the open and ver y general Zilber-Pink conjecture. I will describe a recent result and co njecture of similar flavour which are not formally consequences of the Zi lber-Pink conjecture. DTEND;TZID=Europe/Zurich:20151015T171500 END:VEVENT BEGIN:VEVENT UID:news553@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T101139 DTSTART;TZID=Europe/Zurich:20151008T161500 SUMMARY:Doktorkolloquium: Harry Schmidt DESCRIPTION:For an elliptic curve E its additive extension is an algebraic group G sitting inside an exact sequence of algebraic groups \\r\\n0→Ga →G→E→0 \\r\\nwhere Ga is the additive group. The famous Manin-Mumf ord conjecture\, proved by Hindry for such G\, states that the intersectio n of a curve in G with its set of torsion points is finite unless the cur ve is contained in an algebraic subgroup. We will present a relative vers ion of this theorem for families of additive extensions. Afterwards we wi ll discuss some consequences of this result for classical problems such a s Pell’s equation in polynomials and elementary integration. X-ALT-DESC:For an elliptic curve E its additive extension is an algebraic g roup G sitting inside an exact sequence of algebraic groups \n0→Ga →G→E→0 \nwhere Ga is the additive group. The famous M anin-Mumford conjecture\, proved by Hindry for such G\, states that the in tersection of a curve in G with its set of torsion points is finite unles s the curve is contained in an algebraic subgroup. We will present a rela tive version of this theorem for families of additive extensions. Afterwa rds we will discuss some consequences of this result for classical proble ms such as Pell’s equation in polynomials and elementary integration. DTEND;TZID=Europe/Zurich:20151008T171500 END:VEVENT BEGIN:VEVENT UID:news554@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T101458 DTSTART;TZID=Europe/Zurich:20150924T161500 SUMMARY:Doktorkolloquium: Anna Bohun DESCRIPTION:Several physical phenomena arising in fluid dynamics and kinet ic equations can be modeled by nonlinear transport PDE. Such quantities a re the vorticity of a fluid\, or the density of a collection of particles advected by a velocity field which is highly irregular. The theory of ch aracteristics provides a link between this PDE and the ODE dX/dt=b(t\,X(t \,x))\, where $b$ is the velocity field. Given a vector field with Sobole v or BV regularity and bounded divergence\, the theory of DiPerna-Lions a nd Ambrosio gives a good notion of solution to the ordinary differential equation using the concept of regular Lagrangian flow. I will discuss th e recent works with Crippa-Bouchut regarding Lagrangian flows associated to velocity fields with anisotropic regularity: those with gradient given by the singular integral of an L1 function in some directions\, and the singular integral of a measure in others. This answers positively the que stion of existence of Lagrangian solutions to the Vlasov Poisson and Eule r equations with L1 data. X-ALT-DESC: Several physical phenomena arising in fluid dynamics and kinet ic equations can be modeled by nonlinear transport PDE. Such quantities a re the vorticity of a fluid\, or the density of a collection of particles advected by a velocity field which is highly irregular. The theory of ch aracteristics provides a link between this PDE and the ODE dX/dt=b(t\,X(t \,x))\, where $b$ is the velocity field. Given a vector field with Sobole v or BV regularity and bounded divergence\, the theory of DiPerna-Lions a nd Ambrosio gives a good notion of solution to the ordinary differential equation using the concept of regular Lagrangian flow. I will discuss th e recent works with Crippa-Bouchut regarding Lagrangian flows associated to velocity fields with anisotropic regularity: those with gradient given by the singular integral of an L1 function in some directions \, and the singular integral of a measure in others. This answers positiv ely the question of existence of Lagrangian solutions to the Vlasov Poiss on and Euler equations with L1 data. DTEND;TZID=Europe/Zurich:20150924T171500 END:VEVENT BEGIN:VEVENT UID:news555@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T101627 DTSTART;TZID=Europe/Zurich:20150831T161500 SUMMARY:Doktorkolloquium: Markus Siebenmorgen DTEND;TZID=Europe/Zurich:20150831T171500 END:VEVENT BEGIN:VEVENT UID:news556@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T102957 DTSTART;TZID=Europe/Zurich:20150522T161500 SUMMARY:Perlen-Kolloquium: Enrico Valdinoci DESCRIPTION:We give a simple introduction to the notion of fractional Lapl acian\, starting from the one of the Laplacian\, and presenting detailed  concrete applications in different fields\, such as engineering\, wate r waves\, crystal dislocations and probability.\\r\\nNo previous expertis e on the subject is needed. X-ALT-DESC:We give a simple introduction to the notion of fractional Lapla cian\, \;starting from the one of the Laplacian\, and presenting deta iled \;concrete applications in different fields\, such as engineerin g\, \;water waves\, crystal dislocations and probability.\nNo previou s expertise on the subject is needed. DTEND;TZID=Europe/Zurich:20150522T171500 END:VEVENT BEGIN:VEVENT UID:news557@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190114T103258 DTSTART;TZID=Europe/Zurich:20150521T161500 SUMMARY:Doktorkolloquium: Michaela Mehlin DESCRIPTION:Efficient Explicit Time Integration for the Simulation of Acous tic and Electromagnetic Waves X-ALT-DESC:Efficient Explicit Time Integration for the Simulation of Acoust ic and Electromagnetic Waves DTEND;TZID=Europe/Zurich:20150521T171500 END:VEVENT BEGIN:VEVENT UID:news558@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T155503 DTSTART;TZID=Europe/Zurich:20150305T161500 SUMMARY:Perlen-Kolloquium: Giuseppe Mingione (Università di Parma) DESCRIPTION:Calderòn-Zygmund theory lies at the core of the classical anal ysis of linear partial differential equations of the past century. The bas ic question it tries to address can be put as: Given an equation with assi gned data\, how the qualitative properties of solutions are influenced by those of the data? In other words\, if the given data have some degree of regularity\, how such a regularity reflects in that of the solutions? Opti mal answers have been given in case the equations considered are linear\, starting with the seminal work of Calderòn and Zygmund in the fifties. Th e last years have witnessed a great effort towards a parallel theory that tries to get the same conclusions for nonlinear equations\, obviously via different methods. I will try to give an overview of the whole development \, starting by the classics\, finally coming to the most recent results. X-ALT-DESC: Calderòn-Zygmund theory lies at the core of the classical anal ysis of linear partial differential equations of the past century. The bas ic question it tries to address can be put as: Given an equation with assi gned data\, how the qualitative properties of solutions are influenced by those of the data? In other words\, if the given data have some degree of regularity\, how such a regularity reflects in that of the solutions? Opti mal answers have been given in case the equations considered are linear\, starting with the seminal work of Calderòn and Zygmund in the fifties. Th e last years have witnessed a great effort towards a parallel theory that tries to get the same conclusions for nonlinear equations\, obviously via different methods. I will try to give an overview of the whole development \, starting by the classics\, finally coming to the most recent results. DTEND;TZID=Europe/Zurich:20150305T180000 END:VEVENT BEGIN:VEVENT UID:news559@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T155424 DTSTART;TZID=Europe/Zurich:20140925T161500 SUMMARY:Perlen-Kolloquium: Jean-Philippe Furter (Université de la Rochelle / Basel) DESCRIPTION:Many groups  naturally appearing in mathematics are infinite- dimensional. This is for example (generally) the case for the automorphis m group and the birational transformation group of an affine variety.\\r\ \nIs it possible to endow such groups with an infinite-dimensional algebr aic group (for short: ind-group) structure? Can one endow such groups wit h a topology making them topological groups?\\r\\nFinally\, can one hope to develop a theory of ind-groups generalizing in some sense the well e stablished theory of algebraic groups?\\r\\nI will try to present this s ubject by explaining some of the involved notions. I will consider diffe rent examples\, among which the n-th Cremona group.\\r\\nThis latter grou p is nothing else than the ground field fixing automorphism group of the field of rational functions in n indeterminates. X-ALT-DESC:Many groups  \;naturally appearing in mathematics are infin ite-dimensional. This is for example (generally) the case for the automor phism group and the birational transformation group of an affine variety. \nIs it possible to endow such groups with an infinite-dimensional algebr aic group (for short: ind-group) structure? Can one endow such groups wit h a topology making them topological groups?\nFinally\, can one hope to develop a theory of ind-groups \;generalizing in some sense the well established theory \;of algebraic groups?\nI will try to present this subject by explaining some of \;the involved notions. I will conside r different examples\, \;among which the n-th Cremona group.\nT his latter group is nothing else than \;the ground field fixing automo rphism group \;of the field of rational functions in n indeterm inates. DTEND;TZID=Europe/Zurich:20140925T180000 END:VEVENT BEGIN:VEVENT UID:news560@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T155340 DTSTART;TZID=Europe/Zurich:20140508T161500 SUMMARY:Perlen-Kolloquium: Mariano Giaquinta (Scuola Normale Superiore\, Pi sa) DESCRIPTION:I shall illustrate some of the contributions of Lagrange to the Calculus of Variations. X-ALT-DESC: I shall illustrate some of the contributions of Lagrange to the Calculus of Variations. DTEND;TZID=Europe/Zurich:20140508T173000 END:VEVENT BEGIN:VEVENT UID:news561@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T155313 DTSTART;TZID=Europe/Zurich:20140403T161500 SUMMARY:Perlen-Kolloquium: François Golse (Ecole Polytechnique\, Paris) DESCRIPTION:The kinetic theory of gases\, founded by Maxwell and Boltzmann in the second half of XIXth century\, is a statistical theory describing t he motion of a very large number of gas molecules in the phase space of on e single point particle - i.e. the set of positions and velocities of that particle. However\, some very natural problems in kinetic theory require using a larger phase space\,including some additional variables describing the correlations of the typical moving particle with its environment. The talk will discuss two examples of this situation. X-ALT-DESC: The kinetic theory of gases\, founded by Maxwell and Boltzmann in the second half of XIXth century\, is a statistical theory describing t he motion of a very large number of gas molecules in the phase space of on e single point particle - i.e. the set of positions and velocities of that particle. However\, some very natural problems in kinetic theory require using a larger phase space\,including some additional variables describing the correlations of the typical moving particle with its environment. The talk will discuss two examples of this situation. DTEND;TZID=Europe/Zurich:20140403T173000 END:VEVENT BEGIN:VEVENT UID:news562@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T155209 DTSTART;TZID=Europe/Zurich:20131219T161500 SUMMARY:Perlen-Kolloquium: David Masser (Universität Basel) DESCRIPTION:Functions such as 1/(x(x−λ))½ can always be integrated (with respect to x) in“elementary terms” involving logarithms and exponentials. But not 1/(x(x−1)(x−λ))½ unless λ=0\,1. A more inter esting example is 1/((x−1+λ3)(x(x−1)(x−λ))½)\, which can be done also for λ=(1+(−3)½)/2. In 1981 James Davenport claimed that an arbitr ary such algebraic f(x\,λ) can be integrated for at most finitely many sp ecial complex values λ (unless it can be integrated for a general value o f λ). Umberto Zannier and Idare to hope for a full proof in the next coup le of years\; but for now I will content myself with a general discussion of the problem together with some of the key concepts involved in settling significant special cases. X-ALT-DESC: Functions such as 1/(x(x−λ))½ can always be integrated (with respect to x) in“elementary terms” involving log arithms and exponentials. But not 1/(x(x−1)(x−λ))½ unless λ=0\,1. A more interesting example is 1/((x−1+λ3)(x(x−1)(x−λ))½)\, which can be done also for λ=(1+(−3)½)/2. In 1981 James Davenport claimed that an arbitrary such algebraic f(x\,λ) ca n be integrated for at most finitely many special complex values λ (unles s it can be integrated for a general value of λ). Umberto Zannier and Ida re to hope for a full proof in the next couple of years\; but for now I wi ll content myself with a general discussion of the problem together with s ome of the key concepts involved in settling significant special cases. DTEND;TZID=Europe/Zurich:20131219T190000 END:VEVENT BEGIN:VEVENT UID:news563@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T155648 DTSTART;TZID=Europe/Zurich:20131212T161500 SUMMARY:Perlen-Kolloquium: Jean-Louis Colliot-Thélène (CNRS et Universit é Paris-Sud) DESCRIPTION:Die Brauergruppe von Varietäten kann man zu verschieden Zwecke n benutzen:\\r\\nZeigen\, das eine Varietät nicht rational ist\, d. h.\, ihr Funktionenkörper nicht rein transzendant ist.Wenn der Grundkörper ei n Zahlkörper ist\, zeigen\, daß das Lokal-Global Prinzip für rationale Punkte nicht gilt (Brauer-Maninsche Hindernis).Die Picardgruppe\, d.h. die Klassengruppe von Divisoren\, untersuchen (Tatesche Vermutung).\\r\\nUnve rzweigte Kohomologiegruppen sind Verallgemeinerungen der Brauergruppe. Ich werde erklären\, wie man sie zu ähnlichen Zwecken anwenden kann.  X-ALT-DESC:Die Brauergruppe von Varietäten kann man zu verschieden Zwecken benutzen:\n\nUnverzweigte Kohomologiegruppen sind Verallgemeiner ungen der Brauergruppe. Ich werde erklären\, wie man sie zu ähnlichen Zw ecken anwenden kann. \; DTEND;TZID=Europe/Zurich:20131212T173000 END:VEVENT BEGIN:VEVENT UID:news564@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T155753 DTSTART;TZID=Europe/Zurich:20130606T161500 SUMMARY:Perlen-Kolloquium: Giovanni Alberti (Università di Pisa) DESCRIPTION:The starting point of this talk is a decomposition theorem for sets of measure zero in the plane\, which can be deduced from an elementar y combinatorial result (Dillworth's lemma). Then I will sketch a few appli cations to elementary questions in Geometric Measure Theory and Real Analy sis\, and\, if time permits\, discuss the extension to higher dimensions. Most of these results were obtained together with D. Preiss (Warwick) and M. Csornyei (Chicago).  X-ALT-DESC:The starting point of this talk is a decomposition theorem for s ets of measure zero in the plane\, which can be deduced from an elementary combinatorial result (Dillworth's lemma). Then I will sketch a few applic ations to elementary questions in Geometric Measure Theory and Real Analys is\, and\, if time permits\, discuss the extension to higher dimensions. M ost of these results were obtained together with D. Preiss (Warwick) and M . Csornyei (Chicago). \; DTEND;TZID=Europe/Zurich:20130606T173000 END:VEVENT BEGIN:VEVENT UID:news565@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T155841 DTSTART;TZID=Europe/Zurich:20130425T161500 SUMMARY:Perlen-Kolloquium: Arnaud Beauville (University of Nice) DESCRIPTION:The equation xn +a1xn−1 +...+an = 0 depends on n coefficients a1\,...\,an\, but we all know that after a change of variable x → x+a we can assume a1 = 0\, so only n−1 parameters are needed. Can we get fur ther? After some work of Hermite and others the subject lay dormant till 1 997\, when Buhler and Reichstein introduced the notion of essential dimens ion of a group. I will explain what it is\, and how results of algebraic g eometry (some of them quite involved) allow to solve the problem in degree ≤ 7.  X-ALT-DESC:The equation xn +a1xn−1 +...+ an = 0 depends on n coefficients a1\,...\,an\, but we all know that after a change of variable x → x+a we can as sume a1 = 0\, so only n−1 parameters are needed. Can we get f urther? After some work of Hermite and others the subject lay dormant till 1997\, when Buhler and Reichstein introduced the notion of essential dime nsion of a group. I will explain what it is\, and how results of algebraic geometry (some of them quite involved) allow to solve the problem in degr ee ≤ 7. \; DTEND;TZID=Europe/Zurich:20130425T170000 END:VEVENT BEGIN:VEVENT UID:news566@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T155906 DTSTART;TZID=Europe/Zurich:20130404T161500 SUMMARY:Perlen-Kolloquium: Christian Krattenthaler (Universität Wien) DESCRIPTION:Cyclic sieving is a(n enumerative) phenomenon formulated by Rei ner\, Stanton and White. Bessis and Reiner proposed two conjectures on cyc lic sieving phenomena for the generalised non-crossing partitions associat ed to complex reflection groups of Armstrong and Bessis. I shall first exp lain what cyclic sieving and these generalised non-crossing partitions are about\, and then report the main ideas of a proof of the above two conjec tures. Part of this work is in collaboration with Thomas Müller.  X-ALT-DESC:Cyclic sieving is a(n enumerative) phenomenon formulated by Rein er\, Stanton and White. Bessis and Reiner proposed two conjectures on cycl ic sieving phenomena for the generalised non-crossing partitions associate d to complex reflection groups of Armstrong and Bessis. I shall first expl ain what cyclic sieving and these generalised non-crossing partitions are about\, and then report the main ideas of a proof of the above two conject ures. Part of this work is in collaboration with Thomas Müller. \; DTEND;TZID=Europe/Zurich:20130404T170000 END:VEVENT BEGIN:VEVENT UID:news567@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T155110 DTSTART;TZID=Europe/Zurich:20121206T161500 SUMMARY:Perlen-Kolloquium: Anand Pillay (University of Leeds Transcendence) DESCRIPTION:We have recently shown that there are no algebraic relations ov er C(t) between distinct solutions and their derivatives of a general Pain levé equation\, culminating a line of work starting with Painlevé\, Drac h\, and others. The proof requires an analysis and translation of the exis ting knowledge regarding "irreducibility" and algebraic solutions\, with t he model theory of dierentially closed fields. We explain some of these co ncepts and sketch the proof. (Joint work with my student Nagloo.) X-ALT-DESC:We have recently shown that there are no algebraic relations ove r C(t) between distinct solutions and their derivatives of a general Painl evé equation\, culminating a line of work starting with Painlevé\, Dra ch\, and others. The proof requires an analysis and translation of the exi sting knowledge regarding "\;irreducibility"\; and algebraic solut ions\, with the model theory of di erentially closed fields. We explain s ome of these concepts and sketch the proof. (Joint work with my student Na gloo.) DTEND;TZID=Europe/Zurich:20121206T170000 END:VEVENT BEGIN:VEVENT UID:news568@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T160231 DTSTART;TZID=Europe/Zurich:20121108T161500 SUMMARY:Perlen-Kolloquium: Corinna Ulcigrai (University of Bristol) DESCRIPTION:A mathematical billiard consists of a planar domain where a bal l travels without friction bouncing elastically at the boundary. Motivated by problems in physics and in contrast to an actual game of billiards\, m athematicians study ball trajectories that never hits a pocket and rebound s infinitely off the table walls.  We will explain how\, when the table i s a (rational) polygon\, one can reduce the problem to the study of surfac e flows. We will also present some recent results on coding of billiards i n regular polygons and chaotic properties of area preserving flows on surf aces. X-ALT-DESC:A mathematical billiard consists of a planar domain where a ball travels without friction bouncing elastically at the boundary. Motivated by problems in physics and in contrast to an actual game of billiards\, ma thematicians study ball trajectories that never hits a pocket and rebounds infinitely off the table walls. \; We will explain how\, when the tab le is a (rational) polygon\, one can reduce the problem to the study of su rface flows. We will also present some recent results on coding of billiar ds in regular polygons and chaotic properties of area preserving flows on surfaces. DTEND;TZID=Europe/Zurich:20121108T170000 END:VEVENT BEGIN:VEVENT UID:news569@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T160657 DTSTART;TZID=Europe/Zurich:20120531T161500 SUMMARY:Perlen-Kolloquium: Giulio Caviglia (Purdue University) and Olga Dmi trieva (Stanford University) DESCRIPTION:A monomial order is a total order\, compatible with multiplicat ion\, defined on the set of all monomials of a polynomial ring. In 1920's Macaulay introduced these orderings to characterize all possible Hilbert f unctions of graded ideals by comparing them to monomial ideals. Subsequent ly Gröbner and his student Bruno Buchberger used them to associate to a g raded ideal a set of multivariate polynomials with desirable algorithmic p roperties\, called a Gröbner basis. Gröbner bases have a wide range of a pplications\, not only in algebra and algebraic geometry but also in many sciences in which polynomial models are used. A general principle is that many numerical invariants of a set of polynomials can be computed\, or at least bounded\, by studying certain monomials determined by a Gröbner bas is. \\r\\nIn this lecture I will first give an overview of this principle in both commutative and computational algebra. I will then use monomial or ders to explain the analogies between two distinct\, yet similar\, theorie s in phonology: Optimality Theory and Harmonic Grammars. In particular I w ill show how to use a mathematical object\, called Gröbner fan\, to build models of linguistic typology.  X-ALT-DESC:A monomial order is a total order\, compatible with multiplicati on\, defined on the set of all monomials of a polynomial ring. In 1920's M acaulay introduced these orderings to characterize all possible Hilbert fu nctions of graded ideals by comparing them to monomial ideals. Subsequentl y Gröbner and his student Bruno Buchberger used them to associate to a gr aded ideal a set of multivariate polynomials with desirable algorithmic pr operties\, called a Gröbner basis. Gröbner bases have a wide range of ap plications\, not only in algebra and algebraic geometry but also in many s ciences in which polynomial models are used. A general principle is that m any numerical invariants of a set of polynomials can be computed\, or at l east bounded\, by studying certain monomials determined by a Gröbner basi s. \nIn this lecture I will first give an overview of this principle in bo th commutative and computational algebra. I will then use monomial orders to explain the analogies between two distinct\, yet similar\, theories in phonology: Optimality Theory and Harmonic Grammars. In particular I will s how how to use a mathematical object\, called Gröbner fan\, to build mode ls of linguistic typology. \; DTEND;TZID=Europe/Zurich:20120531T180000 END:VEVENT BEGIN:VEVENT UID:news570@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T161916 DTSTART;TZID=Europe/Zurich:20120503T161500 SUMMARY:Perlen-Kolloquium: Wolfgang L. Wendland (Univerität Stuttgart) DESCRIPTION:This is a lecture on joint work with H. Harbrecht (U. Basel\, S witzerland)\, G. Of (TU. Graz\, Austria) and N. Zorii (Nat. Academy Sci. K iev\, Ukraine).\\r\\nIn Rn \, n≥2\, we study the constructive and numeri cal solution of minimizing the energy relative to the Riesz kernel |x−y| α−n\, where 1<αRn \, n≥2\, we study the constructi ve and numerical solution of minimizing the energy relative to the Riesz k ernel |x−y|α−n\, where 1<\;α<\;n\, for the Gauss vari ational problem\, which is considered for finitely many compact\, mutually disjoint\, boundaryless (n−1)–dimensional Lipschitz manifolds Γ l\, l ∈ L\, each Γl being charged with Borel measures with the sign αl = ±1 prescribed.\nFor Newton potentials\, i. e. the special case α = 2\, this problem goes back to C. F. Gauss who use d it as the model for electrostatic fields. Nowadays it is of interest for the storage of charges as produced by solar electricity modules. The more general Riesz kernels have also applications for finding numerical integr ation formulae on manifolds.\nWe show that the Gauss variational problem o ver an affine cone of Borel measures can alternatively be formulated as a minimum problem over an affine cone of surface distributions belonging to the Sobolev–Slobodetski space H−ε/2(Γ)\, where ε := α −1 and Γ :=∪ \;l∈L Γl. This allows the a pplication of simple layer boundary integral operators on Γ. A correspond ing numerical method is based on the Galerkin–Bubnov discretization with piecewise constant boundary elements. For n = 3 and α = 2\, multipole ap proximation and in the case 1 <\; α <\; 3 = n wavelet matrix compress ion is applied to sparsify the system matrix. For a subclass of these prob lems\, a dual formulation results in linear boundary integral equations al though the original problem is nonlinear. Numerical results are presented to illustrate the approach. \; END:VEVENT BEGIN:VEVENT UID:news571@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T162503 DTSTART;TZID=Europe/Zurich:20111215T161500 SUMMARY:Perlen-Kolloquium: Martin J. Gander (Université de Genève) DESCRIPTION:Der Ursprung des Wissenschaftlichen Rechnens ist weit über die letzten Jahrhunderte verstreut. Er liegt in den Werken der reinen Mathema tik\, in der Erfindung von Methoden zur Untersuchung von mathematischen Ob jekten und zum Beweis von Lehrsätzen. Ein schönes Beispiel ist das berü hmte alternierende Verfahren von Hermann Amandus Schwarz\, entwickelt vor über 140 Jahren\, welches nun zu den besten Algorithmen des parallelen Re chnens geführt hat. Schwarz erfand dieses Verfahren\, um einen Fehler im Beweis vom gefeierten Riemannschen Abbildungssatz zu korrigieren. Ein weit eres Beispiel ist die Methode der finiten Elemente\, welche ihren Ursprung in der Variationsrechnung von Euler und Lagrange aus dem 16. Jahrhundert hat\, und vom Schweizer Walther Ritz\, welcher vor etwas über hundert Jah ren im Alter von nur 31 Jahren einer Tuberkulose erlag\, zur mächtigen nu merischen Methode weitergeführt wurde. Wir werden in diesem Vortrag eine Zeitreise machen durch die Jahrhunderte und dem Pfad folgen\, welcher durc h die Anstrengungen vieler berühmter Mathematiker zu den heutigen Rechenm ethoden auf Hochleistungsrechnern geführt hat.  X-ALT-DESC:Der Ursprung des Wissenschaftlichen Rechnens ist weit über die letzten Jahrhunderte verstreut. Er liegt in den Werken der reinen Mathemat ik\, in der Erfindung von Methoden zur Untersuchung von mathematischen Obj ekten und zum Beweis von Lehrsätzen. Ein schönes Beispiel ist das berüh mte alternierende Verfahren von Hermann Amandus Schwarz\, entwickelt vor über 140 Jahren\, welches nun zu den besten Algorithmen des parallelen Re chnens geführt hat. Schwarz erfand dieses Verfahren\, um einen Fehler im Beweis vom gefeierten Riemannschen Abbildungssatz zu korrigieren. Ein weit eres Beispiel ist die Methode der finiten Elemente\, welche ihren Ursprung in der Variationsrechnung von Euler und Lagrange aus dem 16. Jahrhundert hat\, und vom Schweizer Walther Ritz\, welcher vor etwas über hundert Jah ren im Alter von nur 31 Jahren einer Tuberkulose erlag\, zur mächtigen nu merischen Methode weitergeführt wurde. Wir werden in diesem Vortrag eine Zeitreise machen durch die Jahrhunderte und dem Pfad folgen\, welcher durc h die Anstrengungen vieler berühmter Mathematiker zu den heutigen Rechenm ethoden auf Hochleistungsrechnern geführt hat. \; END:VEVENT BEGIN:VEVENT UID:news572@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T162839 DTSTART;TZID=Europe/Zurich:20111110T161500 SUMMARY:Perlen-Kolloquium: Frits Beukers (Utrecht University) DESCRIPTION:Ever since their inception by Euler and Gauss\, hypergeometric functions have appeared in many different branches of mathematics and math ematical physics. The concept hypergeometric function has also been genera lized in many different directions. In the end of the 1980's Gel’fand\, Kapranov and Zelevinski formulated an elegant framework of so-called A-hyp ergeometric functions\, which encompasses many of the several variable hyp ergeometric functions. In this lecture we explain the concept of A-hyperge ometric function and describe some recent developments on the determinatio n of their monodromy group. The latter gives a conceptual insight into the many relations that exist between hypergeometric functions.  X-ALT-DESC:Ever since their inception by Euler and Gauss\, hypergeometric f unctions have appeared in many different branches of mathematics and mathe matical physics. The concept hypergeometric function has also been general ized in many different directions. In the end of the 1980's Gel’fand\, K apranov and Zelevinski formulated an elegant framework of so-called A-hype rgeometric functions\, which encompasses many of the several variable hype rgeometric functions. In this lecture we explain the concept of A-hypergeo metric function and describe some recent developments on the determination of their monodromy group. The latter gives a conceptual insight into the many relations that exist between hypergeometric functions. \; END:VEVENT BEGIN:VEVENT UID:news573@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T163053 DTSTART;TZID=Europe/Zurich:20110526T161500 SUMMARY:Perlen-Kolloquium: Alexandru Oancea (Université de Strasbourg) DESCRIPTION:The fundamental quantity in Riemannian geometry is the length o f a curve\, whereas the fundamental quantity in symplectic geometry is the area of a surface. From dimension one to dimension two\, from real to com plex\, from particles to strings\, how far can one push the analogy betwee n these two worlds ?  X-ALT-DESC:The fundamental quantity in Riemannian geometry is the length of a curve\, whereas the fundamental quantity in symplectic geometry is the area of a surface. From dimension one to dimension two\, from real to comp lex\, from particles to strings\, how far can one push the analogy between these two worlds ? \; END:VEVENT BEGIN:VEVENT UID:news574@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T163413 DTSTART;TZID=Europe/Zurich:20110512T161500 SUMMARY:Perlen-Kolloquium: Enrico Leuzinger (Karlsruhe Institute of Technol ogy) DESCRIPTION:Wir illustrieren an Hand von einigen Beispielen\, dass Fragen a us der Komplexitäts- und Gruppentheorie (Wortproblem) erstaunlicherweise eng mit Konzepten aus der Differentialgeometrie (Minimalflächen\, isoperi metrische Ungleichungen) zusammenhängen.  X-ALT-DESC:Wir illustrieren an Hand von einigen Beispielen\, dass Fragen au s der Komplexitäts- und Gruppentheorie (Wortproblem) erstaunlicherweise e ng mit Konzepten aus der Differentialgeometrie (Minimalflächen\, isoperim etrische Ungleichungen) zusammenhängen. \; END:VEVENT BEGIN:VEVENT UID:news575@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T163627 DTSTART;TZID=Europe/Zurich:20110428T161500 SUMMARY:Perlen-Kolloquium: Sebastian Baader (Universität Bern) DESCRIPTION:Der euklidische Algorithmus liefert eine Metrik auf euklidische n Rechtecken mit ganzen Seiten\, welche mehr oder weniger (aber nicht gena u!) die Differenz der Flaecheninhalte und des Umfangs angibt. Wie wir sehe n werden\, erlaubt diese Metrik eine voellig unerwartete Interpretation vi a Torusknoten und Kobordismen. Als Anwendung erhalten wir eine relative Th om-Vermutung.  X-ALT-DESC:Der euklidische Algorithmus liefert eine Metrik auf euklidischen Rechtecken mit ganzen Seiten\, welche mehr oder weniger (aber nicht genau !) die Differenz der Flaecheninhalte und des Umfangs angibt. Wie wir sehen werden\, erlaubt diese Metrik eine voellig unerwartete Interpretation via Torusknoten und Kobordismen. Als Anwendung erhalten wir eine relative Tho m-Vermutung. \; END:VEVENT BEGIN:VEVENT UID:news576@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T164257 DTSTART;TZID=Europe/Zurich:20110303T161500 SUMMARY:Perlen-Kolloquium: Michel Waldschmidt (Paris 6) DESCRIPTION:The equation x2−dy2 = ±1\, where the unknowns x and y are po sitive integers while d is a fixed positive integer which is not a square\ , has been mistakenly called with the name of Pell by Euler. It was invest igated by Indian mathematicians since Brahmagupta (628) who solved the cas e d = 92\, next by Bhaskara II (1150) for d = 61 and Narayana (during the 14-th Century) for d = 103. The smallest solution of x2 − dy2 = 1 for th ese values of d are respectively\\r\\n11512 −92·1202 = 1\, 17663190492 −61·2261539802 = 1\\r\\nand\\r\\n2275282 −103·224192 = 1\, \\r\\nhen ce they have not been found by a brute force search! After a short introdu ction to this long history we explain the connection with Diophantine appr oximation and continued fractions\, next we say a few words on more recent developments of the subject. X-ALT-DESC:The equation x2−dy2 = ±1\, where the un knowns x and y are positive integers while d is a fixed positive integer w hich is not a square\, has been mistakenly called with the name of Pell by Euler. It was investigated by Indian mathematicians since Brahmagupta (62 8) who solved the case d = 92\, next by Bhaskara II (1150) for d = 61 and Narayana (during the 14-th Century) for d = 103. The smallest solution of x2 − dy2 = 1 for these values of d are respectivel y\n11512 −92·1202 = 1\, 17663190492 −61·2261539802 = 1\nand\n2275282 −103·224192 = 1\, \nhence they have not been found by a brute force se arch!
After a short introduction to this long history we explain the connection with Diophantine approximation and continued fractions\, next we say a few words on more recent developments of the subject. END:VEVENT BEGIN:VEVENT UID:news577@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T164844 DTSTART;TZID=Europe/Zurich:20101118T161500 SUMMARY:Perlen-Kolloquium: Joachim Rosenthal (Universität Zürich) DESCRIPTION:tba X-ALT-DESC:tba DTEND;TZID=Europe/Zurich:20101118T171500 END:VEVENT BEGIN:VEVENT UID:news578@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190116T165158 DTSTART;TZID=Europe/Zurich:20100930T161500 SUMMARY:Perlen-Kolloquium: Francesco Costantino (IRMA Strasbourg): DESCRIPTION:I will recall the definition of the Kauman brackets of a graph embedded in the three-dimensional sphere. After providing some examples\, I will formulate a general problem on the "asymptotical behavior" of such objects. In the case of planar graphs\, I shall then relate such a problem to the geometry of polyhedra in the hyperbolic space. X-ALT-DESC:I will recall the de finition of the Kau man brackets of a graph embedded in the three-dimensional sphere. After providing some examples\, I will formulate a general problem on the "\;asymptotical behavior&qu ot\; of such objects. In the case of planar graphs\, I shall then relate s uch a problem to the geometry of polyhedra in the hyperbolic space. DTEND;TZID=Europe/Zurich:20100930T171500 END:VEVENT BEGIN:VEVENT UID:news580@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190118T084550 DTSTART;TZID=Europe/Zurich:20100527T000000 SUMMARY:Perlen-Kolloquium: Rinat Kashaev (Université de Genève) DESCRIPTION:The volume conjecture and Chern Simons theory X-ALT-DESC:The volume conjecture and Chern Simons theory END:VEVENT BEGIN:VEVENT UID:news579@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190118T083938 DTSTART;TZID=Europe/Zurich:20100318T000000 SUMMARY:Perlen-Kolloquium: Camillo De Lellis (Universität Zürich) DESCRIPTION:h-Principle and fluid dynamics X-ALT-DESC:h-Principle and fluid dynamics END:VEVENT BEGIN:VEVENT UID:news583@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190118T085316 DTSTART;TZID=Europe/Zurich:20091203T000000 SUMMARY:Perlen-Kolloquium: Gerhard Wanner (Université de Genève) DESCRIPTION:Kepler\, Newton und numerische Mathematik X-ALT-DESC:Kepler\, Newton und numerische Mathematik END:VEVENT BEGIN:VEVENT UID:news582@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190118T085110 DTSTART;TZID=Europe/Zurich:20091126T000000 SUMMARY:Perlen-Kolloquium: Samuel Patterson (Universität Göttingen) DESCRIPTION:Das Leben von Kurt Heegner X-ALT-DESC:Das Leben von Kurt Heegner END:VEVENT BEGIN:VEVENT UID:news581@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190118T084930 DTSTART;TZID=Europe/Zurich:20091015T000000 SUMMARY:Perlen-Kolloquium: Alain Chenciner (Université de Paris 7) DESCRIPTION:Des polygones réguliers aux chorégraphies et aux Hip-Hops X-ALT-DESC:Des polygones réguliers aux chorégraphies et aux Hip-Hops END:VEVENT BEGIN:VEVENT UID:news588@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190118T090902 DTSTART;TZID=Europe/Zurich:20090528T000000 SUMMARY:Perlen-Kolloquium: Yuri Bilu (Université Bordeaux I) DESCRIPTION:Transcendence of automatic numbers(after Adamczewski and Bugeau d) X-ALT-DESC:Transcendence of automatic numbers(after Adamczewski and Bugeaud ) END:VEVENT BEGIN:VEVENT UID:news587@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190118T090539 DTSTART;TZID=Europe/Zurich:20090402T000000 SUMMARY:Perlen-Kolloquium: Matthias Kreck (Universität Bonn) DESCRIPTION:Kann man Mathematik hören? Codes\, Arithmetik und Topologie X-ALT-DESC:Kann man Mathematik hören? Codes\, Arithmetik und Topologie END:VEVENT BEGIN:VEVENT UID:news586@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190118T090426 DTSTART;TZID=Europe/Zurich:20090326T000000 SUMMARY:Perlen-Kolloquium: Ruth Kellerhals (Universität Freiburg\, CH) DESCRIPTION:Symmetrien und Extremaleigenschaften in negativer Krümmung X-ALT-DESC:Symmetrien und Extremaleigenschaften in negativer Krümmung END:VEVENT BEGIN:VEVENT UID:news585@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190118T085724 DTSTART;TZID=Europe/Zurich:20090312T000000 SUMMARY:Perlen-Kolloquium: Duco van Straten (Universität Mainz) DESCRIPTION:Von Amoeben zu Algen: tropische und arktische Einblicke in die Topologie von Laurent Polynomen X-ALT-DESC:Von Amoeben zu Algen: tropische und arktische Einblicke in die T opologie von Laurent Polynomen END:VEVENT BEGIN:VEVENT UID:news584@dmi.unibas.ch DTSTAMP;TZID=Europe/Zurich:20190118T085502 DTSTART;TZID=Europe/Zurich:20090226T000000 SUMMARY:Perlen-Kolloquium: Walter Gautschi (Purdue University) DESCRIPTION:Die Spirale des Theodorus\, numerische Mathematik und spezielle Funktionen X-ALT-DESC:Die Spirale des Theodorus\, numerische Mathematik und spezielle Funktionen END:VEVENT END:VCALENDAR