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Working in the time domain, we show that the location of the singularities and the principal symbol of a potential that is conormal to nested submanifolds $S_2 \subset S_1 \subset \mathbb{R}^n$, for $n \geq 3$, can be recovered from the…

Analysis of PDEs · Mathematics 2011-12-14 Suresh Eswarathasan

The star transform is a generalized Radon transform mapping a function of two variables to its integrals along "star-shaped" trajectories, which consist of a finite number of rays emanating from a common vertex. Such operators appear in…

Mathematical Physics · Physics 2021-04-14 Gaik Ambartsoumian , Mohammad Javad Latifi Jebelli

This article introduces a novel probability distribution model, namely Complex Isotropic {\alpha}-Stable-Rician (CI{\alpha}SR), for characterizing the data histogram of synthetic aperture radar (SAR) images. Having its foundation situated…

Image and Video Processing · Electrical Eng. & Systems 2023-06-08 Mutong Li , Ercan Engin Kuruoglu

The Laplacian $\Delta_{\mathbb{S}^{n-1}}$ on the unit sphere $\mathbb{S}^{n-1}\subset \mathbb{R}^n$ has the property that it can explicitly be expressed in terms of $\Lambda$, the Dirichlet-to-Neumann map of the unit ball, as…

Analysis of PDEs · Mathematics 2025-10-13 Romain Speciel

The aim of this paper is to find new estimates for the norms of functions of the (minus) Laplace operator $\cal L$ on the `$ax+b$' groups. The central part is devoted to spectrally localized wave propagators, that is, functions of the type…

Functional Analysis · Mathematics 2023-07-11 Rauan Akylzhanov , Yulia Kuznetsova , Michael Ruzhansky , Haonan Zhang

We study the stability of the reconstruction of the scattering and absorption coefficients in a stationary linear transport equation from knowledge of the full albedo operator in dimension $n\geq3$. The albedo operator is defined as the…

Mathematical Physics · Physics 2009-02-19 Guillaume Bal , Alexandre Jollivet

This paper considers the backstepping state feedback control of coupled linear parabolic PDEs with spatially varying coefficients and bilateral actuation. By making use of the folding technique, a system representation with unilateral…

Optimization and Control · Mathematics 2021-04-13 Simon Kerschbaum , Joachim Deutscher

We have extended the spectral dynamics formalism introduced by Binney & Spergel, and have implemented a semi-analytic method to represent regular orbits in any potential, making full use of their regularity. We use the spectral analysis…

Astrophysics · Physics 2009-10-31 Y. Copin , H. S. Zhao , P. T. de Zeeuw

Local reconstruction analysis (LRA) is a powerful and flexible technique to study images reconstructed from discrete generalized Radon transform (GRT) data, $g=\mathcal R f$. The main idea of LRA is to obtain a simple formula to accurately…

Numerical Analysis · Mathematics 2025-06-27 Alexander Katsevich

The complex Ginzburg--Landau equation serves as a paradigm of pattern formation and the existence and stability properties of Ginzburg--Landau $m$-armed spiral waves have been investigated extensively. However, many multi-armed spiral waves…

Dynamical Systems · Mathematics 2022-10-18 Isabelle Schneider , Babette de Wolff , Jia-Yuan Dai

The multifractal properties of the Edwards-Anderson order parameter of the short-range Ising spin glass model on d=3 diamond hierarchical lattices is studied via an exact recursion procedure. The profiles of the local order parameter are…

Disordered Systems and Neural Networks · Physics 2009-10-30 E. Nogueira , S. Coutinho , F. D. Nobre , E. M. F. Curado , J. R. L. de Almeida

Doppler reflectometry spatial and wavenumber resolution is analyzed within the framework of the linear Born approximation in slab plasma model. Explicit expression for its signal backscattering spectrum is obtained in terms of wavenumber…

Plasma Physics · Physics 2007-05-23 Alexander Surkov , Evgeniy Gusakov

As an essential part of structure from motion (SfM) and Simultaneous Localization and Mapping (SLAM) systems, motion averaging has been extensively studied in the past years and continues to attract surging research attention. While…

Computer Vision and Pattern Recognition · Computer Science 2020-11-03 Xinyi Li , Lin Yuan , Longin Jan Latecki , Haibin Ling

Let $M\subset S^{n+1}$ be the hypersurface generated by rotating a hypersurface $M_0$ contained in the interior of the unit ball of $\mathbb{R}^{n-k+1}$. More precisely, $M=\{(\sqrt{1-|m|^2}\, y, m):y\in S^k, m\in M_0\}$. We derive the…

Differential Geometry · Mathematics 2025-10-13 Oscar Perdomo

Restoring images degraded by spatially varying blur is a problem encountered in many disciplines such as astrophysics, computer vision or biomedical imaging. One of the main challenges to perform this task is to design efficient numerical…

Optimization and Control · Mathematics 2015-10-13 Paul Escande , Pierre Weiss

We study the structure of normal operators of double fibration transforms with conjugate points. Examples of double fibration transforms include Radon transforms, $d$-plane transforms on the Euclidean space, geodesic X-ray transforms,…

Analysis of PDEs · Mathematics 2025-12-29 Hiroyuki Chihara

We focus on a specific use case in anomaly detection where the distribution of normal samples is supported by a lower-dimensional manifold. Here, regularized autoencoders provide a popular approach by learning the identity mapping on the…

Computer Vision and Pattern Recognition · Computer Science 2024-05-14 Alexander Bauer , Shinichi Nakajima , Klaus-Robert Müller

Let $H$ be a Schr\"odinger type operator with long-range perturbation. We study the wave front set of the distribution kernel of $(H-\lambda\mp i0)^{-1}$, where $\lambda$ is in the absolutely continous spectrumof $H$.The result is a…

Analysis of PDEs · Mathematics 2016-04-26 Shu Nakamura

We construct (modified) scattering operators for the Vlasov-Poisson system in three dimensions, mapping small asymptotic dynamics as $t\to -\infty$ to asymptotic dynamics as $t\to +\infty$. The main novelty is the construction of modified…

Analysis of PDEs · Mathematics 2021-01-06 Patrick Flynn , Zhimeng Ouyang , Benoit Pausader , Klaus Widmayer

We introduce Laplace transformations of 2D semi-discrete hyperbolic Schroedinger operators and show their relation to a semi-discrete 2D Toda lattice. We develop the algebro-geometric spectral theory of 2D semi-discrete hyperbolic…

Mathematical Physics · Physics 2007-05-23 Alexei A. Oblomkov , Alexei V. Penskoi