Computational high frequency wave propagation

B Engquist, O Runborg - Acta numerica, 2003 - cambridge.org
Numerical simulation of high frequency acoustic, elastic or electro-magnetic wave
propagation is important in many applications. Recently the traditional techniques of ray …

[PDF][PDF] Mathematical models and numerical methods for high frequency waves

O Runborg - Commun. Comput. Phys, 2007 - global-sci.org
The numerical approximation of high frequency wave propagation is important in many
applications. Examples include the simulation of seismic, acoustic, optical waves and …

High frequency limit for a chain of harmonic oscillators with a point Langevin thermostat

T Komorowski, S Olla, L Ryzhik, H Spohn - Archive for Rational Mechanics …, 2020 - Springer
We consider an infinite chain of coupled harmonic oscillators with a Langevin thermostat at
the origin. In the high frequency limit, we establish the reflection-transmission coefficients for …

An introduction to Eulerian geometrical optics (1992–2002)

JD Benamou - Journal of scientific computing, 2003 - Springer
An Introduction to Eulerian Geometrical Optics (1992–2002) Page 1 63 0885-7474/03/1200-0063/0
© 2003 Plenum Publishing Corporation Journal of Scientific Computing, Vol. 19, Nos. 1–3 …

High frequency limit of the Helmholtz equations

JD Benamou, F Castella, T Katsaounis… - Revista matemática …, 2002 - ems.press
We derive the high frequency limit of the Helmholtz equations in terms of quadratic
observables. We prove that it can be written as a stationary Liouville equation with source …

Some new results in multiphase geometrical optics

O Runborg - ESAIM: Mathematical Modelling and Numerical …, 2000 - cambridge.org
In order to accommodate solutions with multiple phases, corresponding to crossing rays, we
formulate geometrical optics for the scalar wave equation as a kinetic transport equation set …

Energy concentration and Sommerfeld condition for Helmholtz equation with variable index at infinity

B Perthame, L Vega - Geometric And Functional Analysis, 2008 - Springer
We consider the Helmholtz equation with a variable index of refraction n (x), which is not
necessarily constant at infinity but can have an angular dependency like n (x) → n_ ∞ (x/| x|) …

The radiation condition at infinity for the high-frequency Helmholtz equation with source term: a wave-packet approach

F Castella - Journal of Functional Analysis, 2005 - Elsevier
We consider the high-frequency Helmholtz equation with a given source term, and a small
absorption parameter α> 0. The high-frequency (or: semi-classical) parameter is ɛ> 0. We …

High-frequency limit of the Helmholtz equation with variable refraction index

XP Wang, P Zhang - Journal of Functional Analysis, 2006 - Elsevier
We study the high-frequency limit of the Helmholtz equation with variable refraction index
and a source term concentrated near a p-dimensional affine subspace. Under some …

Gaussian beam methods for the Helmholtz equation

H Liu, J Ralston, O Runborg, NM Tanushev - SIAM Journal on Applied …, 2014 - SIAM
In this work we construct Gaussian beam approximations to solutions of the high frequency
Helmholtz equation with a localized source. Under the assumption of nontrap** rays we …