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UID:news857@dmi.unibas.ch
DTSTAMP;TZID=Europe/Zurich:20190402T151711
DTSTART;TZID=Europe/Zurich:20190412T110000
SUMMARY:Seminar in Numerical Analysis: Chris Stolk (University of Amsterdam
 )
DESCRIPTION:In this talk I discuss a recently developed finite difference d
 iscretisation of the Helmholtz equation and some solution methods for the 
 resulting linear systems. In high-frequency Helmholtz problems\, pollution
  errors\, due to numerical dispersion\, are a main source of error. We wil
 l show that such errors can be strongly reduced compared to other schemes\
 , including high-order finite elements\, by selecting coefficients for the
  discrete system that maximise the accuracy of geometrical optics phases a
 nd amplitudes. Such low dispersion schemes are of interest by themselves\,
  but can also be used to improve the efficiency of multigrid schemes. Comp
 utation times for a solver combining a multigrid method with domain decomp
 osition compare well to those of alternative methods.For further informati
 on about the seminar\, please visit this webpage.
X-ALT-DESC: In this talk I discuss a recently developed finite difference d
 iscretisation of the Helmholtz equation and some solution methods for the 
 resulting linear systems. In high-frequency Helmholtz problems\, pollution
  errors\, due to numerical dispersion\, are a main source of error. We wil
 l show that such errors can be strongly reduced compared to other schemes\
 , including high-order finite elements\, by selecting coefficients for the
  discrete system that maximise the accuracy of geometrical optics phases a
 nd amplitudes. Such low dispersion schemes are of interest by themselves\,
  but can also be used to improve the efficiency of multigrid schemes. Comp
 utation times for a solver combining a multigrid method with domain decomp
 osition compare well to those of alternative methods.<br /><br />For furth
 er information about the seminar\, please visit this <link de/forschung/ma
 thematik/seminar-in-numerical-analysis/ - - "Opens internal link in curren
 t window">webpage</link>.  
DTEND;TZID=Europe/Zurich:20190412T120000
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