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This paper developed a systematic strategy establishing RBF on the wavelet analysis, which includes continuous and discrete RBF orthonormal wavelet transforms respectively in terms of singular fundamental solutions and nonsingular general…

Symbolic Computation · Computer Science 2007-05-23 W. Chen

This paper is concerned with the multi-frequency factorization method for imaging the support of a wave-number-dependent source function. It is supposed that the source function is given by the inverse Fourier transform of some…

Numerical Analysis · Mathematics 2024-01-02 Hongxia Guo , Guanghui Hu

In this paper, we have studied continuous fractional wavelet transform (CFrWT) in $n$-dimensional Euclidean space $\mathbb{R}^n$ with dilation parameter $\boldsymbol a=(a_{1},a_{2},\ldots,a_{n}),$ such that none of $a_{i}'s$ are zero.…

Functional Analysis · Mathematics 2019-12-20 Amit K. Verma , Bivek Gupta

Global radial basis function (RBF) collocation methods with inifinitely smooth basis functions for partial differential equations (PDEs) work in general geometries, and can have exponential convergence properties for smooth solution…

Numerical Analysis · Mathematics 2020-01-31 Elisabeth Larsson , Ulrika Sundin

Let $Z^H= \{Z^H(t), t \in \R^N\}$ be a real-valued $N$-parameter harmonizable fractional stable sheet with index $H = (H_1, \ldots, H_N) \in (0, 1)^N$. We establish a random wavelet series expansion for $Z^H$ which is almost surely…

Probability · Mathematics 2019-03-12 Antoine Ayache , Narn-Rueih Shieh , Yimin Xiao

In this paper we extend analysis of the WaveHoltz iteration -- a time-domain iterative method for the solution of the Helmholtz equation. We expand the previous analysis of energy conserving problems and prove convergence of the WaveHoltz…

Numerical Analysis · Mathematics 2022-05-26 Fortino Garcia , Daniel Appelö , Olof Runborg

Diffusion probability models have shown significant promise in offline reinforcement learning by directly modeling trajectory sequences. However, existing approaches primarily focus on time-domain features while overlooking frequency-domain…

Machine Learning · Computer Science 2025-09-25 Yifu Luo , Yongzhe Chang , Xueqian Wang

The Helmholtz equation in one dimension, which describes the propagation of electromagnetic waves in effectively one-dimensional systems, is equivalent to the time-independent Schr\"odinger equation. The fact that the potential term…

Classical Physics · Physics 2021-09-15 Farhang Loran , Ali Mostafazadeh

This work analyzes the forward and inverse scattering series for scalar waves based on the Helmholtz equation and the diffuse waves from the time-independent diffusion equation, which are important PDEs in various applications. Different…

Analysis of PDEs · Mathematics 2023-04-19 Srinath Mahankali , Yunan Yang

It is known that the continuous wavelet transform of a function $f$ decays very rapidly near the points where $f$ is smooth, while it decays slowly near the irregular points. This property allows one to precisely identify the singular…

Functional Analysis · Mathematics 2007-05-23 Gitta Kutyniok , Demetrio Labate

In this paper we study nonlinear Helmholtz equations with sign-changing diffusion coefficients on bounded domains. The existence of an orthonormal basis of eigenfunctions is established making use of weak T-coercivity theory. All…

Analysis of PDEs · Mathematics 2021-12-22 Rainer Mandel , Zoïs Moitier , Barbara Verfürth

The Differential Fourier Holography (DFH) gives an exact mathematical solution of the inverse problem of diffraction in the Fraunhofer regime. After the first publication [1] the Differential Fourier Holography was successfully applied in…

Optics · Physics 2016-04-20 Sergey G. Podorov , Eckhart Förster

Over the last ten years, results from [Melenk-Sauter, 2010], [Melenk-Sauter, 2011], [Esterhazy-Melenk, 2012], and [Melenk-Parsania-Sauter, 2013] decomposing high-frequency Helmholtz solutions into "low"- and "high"-frequency components have…

Analysis of PDEs · Mathematics 2022-08-02 Jeffrey Galkowski , David Lafontaine , Euan A. Spence , Jared Wunsch

We study compressible MHD turbulence, which holds key to many astrophysical processes, including star formation and cosmic ray propagation. To account for the variations of the magnetic field in the strongly turbulent fluid we use wavelet…

Astrophysics of Galaxies · Physics 2015-05-18 Grzegorz Kowal , Alex Lazarian

This paper concerns an inverse elastic scattering problem which is to determine the location and the shape of a rigid obstacle from the phased or phaseless far-field data for a single incident plane wave. By introducing the Helmholtz…

Analysis of PDEs · Mathematics 2018-12-03 Heping Dong , Jun Lai , Peijun Li

A novel perturbative method, proposed by Panda {\it et al.} [1] to solve the Helmholtz equation in two dimensions, is extended to three dimensions for general boundary surfaces. Although a few numerical works are available in the literature…

Mathematical Physics · Physics 2016-06-21 Subhasis Panda , S. Pratik Khastgir

In this paper, we investigate 1D elliptic equations $-\nabla\cdot (a\nabla u)=f$ with rough diffusion coefficients $a$ that satisfy $0<a_{\min}\le a\le a_{\max}<\infty$ and $f\in L_2(\Omega)$. To achieve an accurate and robust numerical…

Numerical Analysis · Mathematics 2024-11-01 Qiwei Feng , Bin Han

The vector electric-field Helmholtz equation, containing cross-polarization terms, is factored to produce both pseudo-differential and exponential operator forms of a three-dimensional, one-way, vector, wave equation for propagation through…

Computational Physics · Physics 2024-10-24 Laurence Keefe , Austin McDaniel , Max Cubillos , Ilya Zilberter , Timothy Madden

This paper studies a prototype of inverse obstacle scattering problems whose governing equation is the Helmholtz equation in two dimensions. An explicit method to extract information about the location and shape of unknown obstacles from…

Analysis of PDEs · Mathematics 2011-09-21 Masaru Ikehata

A rigorous approach for solving canonical circular open-ended dielectric-lined waveguide diffraction problems is presented. This is continuation of our recent paper [1] where a simpler case of uniform dielectric filling has been considered.…

Accelerator Physics · Physics 2022-06-15 Sergey N. Galyamin , Viktor V. Vorobev