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We present a modified Front Tracking (mFT) scheme for hyperbolic systems of conservation laws in one space dimension, in which we allow arbitrarily large nonlinear waves. We build the scheme by introducing and solving a ``generalized…

Analysis of PDEs · Mathematics 2025-04-30 Manas Bhatnagar , Robin Young

We establish logarithmic local energy decay for wave equations with a varying wavespeed in dimensions two and higher, where the wavespeed is assumed to be a short range perturbation of unity with mild radial regularity. The key ingredient…

Analysis of PDEs · Mathematics 2025-09-12 Gayana Jayasinghe , Katrina Morgan , Jacob Shapiro , Mengxuan Yang

Numerically solving the 2D Helmholtz equation is widely known to be very difficult largely due to its highly oscillatory solution, which brings about the pollution effect. A very fine mesh size is necessary to deal with a large wavenumber…

Analysis of PDEs · Mathematics 2022-05-17 Bin Han , Michelle Michelle

This paper concerns the inverse source problems for the time-harmonic elastic and electromagnetic wave equations. The goal is to determine the external force and the electric current density from boundary measurements of the radiated wave…

Analysis of PDEs · Mathematics 2018-08-17 Gang Bao , Peijun Li , Yue Zhao

In this article, we discuss about the resolution of the Riemann problem for a 2x2 system in nonconservative form exhibiting parabolic degeneracy. The system can be perceived as the limiting equation (depending on a parameter tending to 0)…

Analysis of PDEs · Mathematics 2014-01-06 Anupam Pal Choudhury

We consider a fixed angle inverse scattering problem in the presence of a known Riemannian metric. First, assuming a no caustics condition, we study the direct problem by utilizing the progressing wave expansion. Under a symmetry assumption…

Analysis of PDEs · Mathematics 2021-07-21 Shiqi Ma , Mikko Salo

In this work we discuss an approximate model for the propagation of deep irrotational water waves, specifically the model obtained by keeping only quadratic nonlinearities in the water waves system under the Zakharov/Craig-Sulem…

Analysis of PDEs · Mathematics 2025-01-06 Vincent Duchêne , Benjamin Melinand

In a recent paper (Ant\'on et al. 2010) we have derived sets of right and left eigenvectors of the Jacobians of the relativistic MHD equations, which are regular and span a complete basis in any physical state including degenerate ones. We…

High Energy Astrophysical Phenomena · Physics 2010-12-14 J. M. Ibáñez , M. A. Aloy , P. Mimica , L. Antón , J. A. Miralles , J. M. Martí

We apply the version of the method of simplest equation called modified method of simplest equation for obtaining exact traveling wave solutions of a class of equations that contain as particular case a nonlinear PDE that models shallow…

Exactly Solvable and Integrable Systems · Physics 2017-09-18 Nikolay K. Vitanov , Tsvetelina I. Ivanova

The main features of a three dimensional, high-resolution special relativistic hydro code based on relativistic Riemann solvers are described. The capabilities and performance of the code are discussed. In particular, we present the results…

Astrophysics · Physics 2009-10-31 M. A. Aloy , J. M. Ibanez , J. M. Marti , E. Muller

This article is devoted to forward and inverse problems associated with time-independent semilinear nonlocal wave equations. We first establish comprehensive well-posedness results for some semilinear nonlocal wave equations. The main…

Analysis of PDEs · Mathematics 2024-02-09 Yi-Hsuan Lin , Teemu Tyni , Philipp Zimmermann

A modified HLLC-type contact preserving Riemann solver for incompressible two-phase flows using the artificial compressibility formulation is presented. Here, the density is omitted from the pressure evolution equation. Also, while…

Computational Physics · Physics 2022-07-14 Sourabh P. Bhat , J. C. Mandal

In this paper, it is shown how a combination of approximate symmetries of a nonlinear wave equation with small dissipations and singularity analysis provides exact analytic solutions. We perform the analysis using the Lie symmetry algebra…

Mathematical Physics · Physics 2019-09-24 Alfred Michel Grundland , Alexander Hariton

This is the second in a series of papers on the construction and validation of a three-dimensional code for the solution of the coupled system of the Einstein equations and of the general relativistic hydrodynamic equations, and on the…

General Relativity and Quantum Cosmology · Physics 2009-11-07 J. Font , T. Goodale , S. Iyer , M. Miller , L. Rezzolla , E. Seidel , N. Stergioulas , W. Suen , M. Tobias

The problem of estimating the initial state of 1-D wave equations with globally Lipschitz nonlinearities from boundary measurements on a finite interval was solved recently by using the sequence of forward and backward observers, and…

Systems and Control · Computer Science 2016-02-25 Emilia Fridman , Maria Terushkin

For a one-dimensional wave equation, we consider a mixed problem in a curvilinear half-strip. The initial conditions have a first-kind discontinuity at one point. The mixed problem models the problem of a longitudinal impact on a finite…

Analysis of PDEs · Mathematics 2025-10-20 Viktor I. Korzyuk , Jan V. Rudzko , Vladislav V. Kolyachko

The dynamical behavior resulting from an initial discontinuity in focusing media is investigated using a combination of numerical simulations and Whitham modulation theory for the focusing nonlinear Schrodinger equation. Initial conditions…

Pattern Formation and Solitons · Physics 2018-12-05 Gino Biondini

Exact solutions describing the Rayleigh-Bloch waves for the two-dimensional Helmholtz equation are constructed in the case when the refractive index is a sum of a constant and a small amplitude function which is periodic in one direction…

Mathematical Physics · Physics 2018-06-13 A. Merzon , P. Zhevandrov , M. I. Romero Rodríguez , J. E. De la Paz Méndez

The paper proposes a second-order accurate direct Eulerian generalized Riemann problem (GRP) scheme for the spherically symmetric general relativistic hydrodynamical (RHD) equations and a second-order accurate discretization for the…

Numerical Analysis · Mathematics 2016-07-29 Kailiang Wu , Huazhong Tang

In this introductory work I will present the Finite Difference method for hyperbolic equations, focusing on a method which has second order precision both in time and space (the so-called staggered leapfrog method) and applying it to the…

Computational Physics · Physics 2007-05-23 Artur B. Adib