Applied Math Seminar
The Applied Math Seminar hosts a wide range of talks in fields such as applied analysis, mathematical biology, fluid dynamics and electromagnetics, numerical computation, etc.
The seminar usually meets at 2:30pm on Fridays in room 1302 of Warren Weaver Hall.
Please email oneil@cims.nyu.edu with suggestions for speakers. If you would like to be added to the mailing list, please send an email to cims-ams+subscribe@nyu.edu from the address at which you wish to receive announcements.
Seminar Organizer(s): Mike O'Neil
Upcoming Events
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Friday, October 3, 20252:30PM, Warren Weaver Hall 1302
Infinity in a Nullshell: Solving Wave Equations on Unbounded Domains
Anil Zenginoglu, U MarylandSynopsis:
When wave propagation problems are posed on unbounded domains, most numerical solvers rely on truncation, such as absorbing boundary conditions or perfectly matched layers (PML). I will describe a geometric alternative that solves the original exterior problem numerically: spatial compactification combined with a time shift that places infinity as a characteristic (null) boundary on the computational grid. This method links ideas between Lorentzian geometry and hyperbolic PDEs.
In the frequency domain, the time shift acts as a rephasing that keeps oscillations bounded so the effective wavenumber remains finite after compactification. In the time domain, the transformed first-order system is symmetric hyperbolic with maximally dissipative boundaries, ensuring stability and tracking energy decay.
For practical applications, a Null Infinity Layer (NIL) can wrap any interior mesh by a layer of finite thickness representing the unbounded exterior domain. I will present numerical experiments of benchmark scattering problems showing that NIL has comparable accuracy to PML while providing acces to the far-field.
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Friday, November 7, 20252:30PM, Warren Weaver Hall 1302
TBA
Cristina Rea, MIT -
Friday, November 14, 20252:30PM, Warren Weaver Hall 1302
TBD
Hanwen Zhang, Yale -
Friday, December 5, 20252:30PM, Warren Weaver Hall 1302
TBD
Jason Kaye, Flatiron Institute