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Related papers: A sharp stability estimate in tensor tomography

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In this paper we develop and test a fully conservative SPH scheme based on a tensor formulation that can be applied to simulate astrophysical systems. In the proposed scheme, derivatives are calculated from an integral expression that leads…

Instrumentation and Methods for Astrophysics · Physics 2015-06-03 Domingo Garcia-Senz , Ruben M. Cabezon , Jose Antonio Escartin

This paper concerns the imaging of a complex-valued anisotropic tensor {\gamma} = {\sigma}+{\iota}{\omega}{\epsilon} from knowledge of several inter magnetic fields H where H satisfies the anisotropic Maxwell system on a bounded domain with…

Analysis of PDEs · Mathematics 2015-01-27 Chenxi Guo , Guillaume Bal

Signal sampling and reconstruction is a fundamental engineering task at the heart of signal processing. The celebrated Shannon-Nyquist theorem guarantees perfect signal reconstruction from uniform samples, obtained at a rate twice the…

Signal Processing · Electrical Eng. & Systems 2020-02-19 Charilaos I. Kanatsoulis , Xiao Fu , Nicholas D. Sidiropoulos , Mehmet Akçakaya

We show that on simple surfaces the geodesic ray transform acting on solenoidal symmetric tensor fields of arbitrary order is injective. This solves a long standing inverse problem in the two-dimensional case.

Differential Geometry · Mathematics 2012-11-13 Gabriel P. Paternain , Mikko Salo , Gunther Uhlmann

We prove a global logarithmic stability estimate for the Gel'fand-Calderon inverse problem on a two-dimensional domain.

Analysis of PDEs · Mathematics 2011-03-01 Roman Novikov , Matteo Santacesaria

This article extends the author's past work [Inv. Probl. Imaging, 10:2 (2016), 433--459] to attenuated X-ray transforms, where the attenuation is complex-valued and only depends on position. We give a positive and constructive answer to the…

Analysis of PDEs · Mathematics 2017-11-03 François Monard

We solve tensor balancing, rescaling an Nth order nonnegative tensor by multiplying N tensors of order N - 1 so that every fiber sums to one. This generalizes a fundamental process of matrix balancing used to compare matrices in a wide…

Methodology · Statistics 2018-10-30 Mahito Sugiyama , Hiroyuki Nakahara , Koji Tsuda

We prove a new global stability estimate for the Gel'fand-Calder\'on inverse problem on a two-dimensional bounded domain or, more precisely, the inverse boundary value problem for the equation $-\Delta \psi + v\, \psi = 0$ on $D$, where $v$…

Analysis of PDEs · Mathematics 2014-02-07 Matteo Santacesaria

We present a technique for recovering a vector field and a symmetric $2$-tensor field, both real-valued and compactly supported in some strictly convex bounded domain with smooth boundary in the Euclidean plane, from the sum of their…

Analysis of PDEs · Mathematics 2025-05-06 Rahul Bhardwaj , Karishman B. Solanki

We show that the spectral norm of a $d$-mode real or complex symmetric tensor in $n$ variables can be computed by finding the fixed points of the corresponding polynomial map. For a generic complex symmetric tensor the number of fixed…

Optimization and Control · Mathematics 2020-01-17 Shmuel Friedland , Li Wang

We study inverse problems in anisotropic elasticity using tools from algebraic geometry. The singularities of solutions to the elastic wave equation in dimension $n$ with an anisotropic stiffness tensor have propagation kinematics captured…

Differential Geometry · Mathematics 2025-05-01 Maarten V. de Hoop , Joonas Ilmavirta , Matti Lassas , Anthony Várilly-Alvarado

Using the language of twisted skew-commutative algebras, we define \emph{secondary representation stability}, a stability pattern in the {\it unstable} homology of spaces that are representation stable in the sense of Church, Ellenberg, and…

Algebraic Topology · Mathematics 2019-10-23 Jeremy Miller , Jennifer C. H. Wilson

This is the sequel to our first paper concerning the balanced embedding of a non-compact complex manifold into an infinite-dimensional projective space. We prove the uniqueness of such an embedding. The proof relies on fine estimates of the…

Complex Variables · Mathematics 2023-11-21 Jingzhou Sun

In this work, a tensor completion problem is studied, which aims to perfectly recover the tensor from partial observations. The existing theoretical guarantee requires the involved transform to be orthogonal, which hinders its applications.…

Machine Learning · Computer Science 2024-08-16 Li Ge , Lin Chen , Yudong Chen , Xue Jiang

A representation for the sharp coefficient in a pointwise estimate for the gradient of a generalized Poisson integral of a function $f$ on ${\mathbb R}^{n-1}$ is obtained under the assumption that $f$ belongs to $L^p$. It is assumed that…

Analysis of PDEs · Mathematics 2017-09-12 Gershon Kresin , Vladimir Maz'ya

Let S be a triangulated 2-sphere with fixed triangulation T. We apply the methods of thin position from knot theory to obtain a simple version of the three geodesics theorem for the 2-sphere [5]. In general these three geodesics may be…

Geometric Topology · Mathematics 2014-09-11 Abigail Thompson

We prove a sharp H\"older estimate for solutions of linear two-dimensional, divergence form elliptic equations with measurable coefficients, such that the matrix of the coefficients is symmetric and has {\em unit determinant}. Our result…

Analysis of PDEs · Mathematics 2007-05-23 Tonia Ricciardi

We propose a robust and scalable procedure for general optimization and inference problems on manifolds leveraging the classical idea of `median-of-means' estimation. This is motivated by ubiquitous examples and applications in modern data…

Methodology · Statistics 2020-06-16 Lizhen Lin , Drew Lazar , Bayan Sarpabayeva , David B. Dunson

We consider the problem of reconstructing the intrinsic geometry of a manifold from noisy pairwise distance observations. Specifically, let $M$ denote a diameter 1 d-dimensional manifold and $\mu$ a probability measure on $M$ that is…

Machine Learning · Statistics 2025-11-18 Charles Fefferman , Jonathan Marty , Kevin Ren

We prove a general representation stability result for polynomial coefficient systems which lets us prove representation stability and secondary homological stability for many families of groups with polynomial coefficients. This gives two…

Algebraic Topology · Mathematics 2021-06-22 Jeremy Miller , Peter Patzt , Dan Petersen