English
Related papers

Related papers: Universal inversion formulas for recovering a func…

200 papers

In the article [11] of L. Kunyansky a symmetric integral identity for Bessel functions of the first and second kind was proved in order to obtain an explicit inversion formula for the spherical mean transform where our data is given on the…

Analysis of PDEs · Mathematics 2019-05-22 Yehonatan Salman

Orbit recovery is a central problem in both mathematics and applied sciences, with important applications to structural biology. This paper focuses on recovering generic orbits of functions on ${\mathbb R}^{n}$ and the sphere $S^{n-1}$…

Numerical Analysis · Mathematics 2025-08-06 Tamir Bendory , Dan Edidin , Josh Katz , Shay Kreymer

In this paper, we derive explicit reconstruction formulas for two common measurement geometries: a plane and a sphere. The problem is formulated as inverting the forward operator $R^a$, which maps the initial source to the measured wave…

Analysis of PDEs · Mathematics 2025-08-27 Cong Shi

The present article proposes a partial answer to the explicit inversion of the tensor tomography problem in two dimensions, by proving injectivity over certain kinds of tensors and providing reconstruction formulas for them. These tensors…

Analysis of PDEs · Mathematics 2015-06-18 François Monard

Universal Drinfeld twists are inner automorphisms which relate the coproduct of a quantum enveloping algebra to the coproduct of the undeformed enveloping algebra. Even though they govern the deformation theory of classical symmetries and…

Quantum Algebra · Mathematics 2007-05-23 Christian Blohmann

This paper is concerned with the ubiquitous inverse problem of recovering an unknown function u from finitely many measurements possibly affected by noise. In recent years, inversion methods based on linear approximation spaces were…

Numerical Analysis · Mathematics 2022-10-06 Albert Cohen , Matthieu Dolbeault , Olga Mula , Agustin Somacal

The cone-beam transform consists of integrating a function defined on the three-dimensional space along every ray that starts on a certain scanning set. Based on Grangeat's formula, Louis [2016, Inverse Problems 32 115005] states…

Numerical Analysis · Mathematics 2021-08-13 Michael Quellmalz , Ralf Hielscher , Alfred K. Louis

We consider a region $M$ in $\mathbb{R}^n$ with boundary $\partial M$ and a metric $g$ on $M$ conformal to the Euclidean metric. We analyze the inverse problem, originally formulated by Dix, of reconstructing $g$ from boundary measurements…

Analysis of PDEs · Mathematics 2012-12-04 Maarten V. de Hoop , Sean F. Holman , Einar Iversen , Matti Lassas , Bjørn Ursin

The article suggests a new approach what is called a consistency method for the inversion of the spherical Radon transform in 2D with detectors on a line. It is known that there is not an exact inversion formula in 2D. By means of the…

Numerical Analysis · Mathematics 2017-05-31 Rafik Aramyan

The main purpose of this paper is to compute all irreducible spherical functions on $G=\SU(3)$ of arbitrary type $\delta\in \hat K$, where $K={\mathrm{S}}(\mathrm{U}(2)\times\mathrm{U}(1))\simeq\mathrm{U}(2)$. This is accomplished by…

Representation Theory · Mathematics 2007-05-23 F. A. Grunbaum , I. Pacharoni , J. Tirao

In tomographic reconstruction, the goal is to reconstruct an unknown object from a collection of line integrals. Given a complete sampling of such line integrals for various angles and directions, explicit inverse formulas exist to…

Numerical Analysis · Mathematics 2018-01-18 Tristan van Leeuwen , Simon Maretzke , K. Joost Batenburg

Generic 3D reconstruction from a single image is a difficult problem. A lot of data loss occurs in the projection. A domain based approach to reconstruction where we solve a smaller set of problems for a particular use case lead to greater…

Computer Vision and Pattern Recognition · Computer Science 2016-06-21 Atishay Jain

Spherical means are well-known useful tool in the theory of partial differential equations with applications to solving hyperbolic and ultrahyperbolic equations and problems of integral geometry, tomography and Radon transforms. We…

Classical Analysis and ODEs · Mathematics 2016-10-17 E. L. Shishkina , S. M. Sitnik

Subspaces obtained by the orthogonal projection of locally supported square-integrable vector fields onto the Hardy spaces $H_+(\mathbb{S})$ and $H_-(\mathbb{S})$, respectively, play a role in various inverse potential field problems since…

Numerical Analysis · Mathematics 2023-07-06 Christian Gerhards , Xinpeng Huang

We propose a new approach to constructing globally strictly convex objective functional in a 1-D inverse medium scattering problem using multi-frequency backscattering data. The global convexity of the proposed objective functional is…

Numerical Analysis · Mathematics 2024-12-20 Thanh T. Nguyen , Michael V. Klibanov

We propose an algorithm for robust recovery of the spherical harmonic expansion of functions defined on the d-dimensional unit sphere $\mathbb{S}^{d-1}$ using a near-optimal number of function evaluations. We show that for any $f \in…

Numerical Analysis · Mathematics 2022-03-01 Amir Zandieh , Insu Han , Haim Avron

From the optimization point of view, a difficulty with parallel MRI with simultaneous coil sensitivity estimation is the multiplicative nature of the non-linear forward operator: the image being reconstructed and the coil sensitivities…

Numerical Analysis · Mathematics 2018-02-06 Yonggui Zhu , Tuomo Valkonen

The problem of image reconstruction in thermoacoustic tomography requires inversion of a generalized Radon transform, which integrates the unknown function over circles in 2D or spheres in 3D. The paper investigates implementation of the…

Numerical Analysis · Mathematics 2007-05-23 Gaik Ambartsoumian , Sarah K. Patch

Under investigation is the problem of finding the best approximation of a function in a Hilbert space subject to convex constraints and prescribed nonlinear transformations. We show that in many instances these prescriptions can be…

Functional Analysis · Mathematics 2021-06-17 Patrick L. Combettes , Zev C. Woodstock

Inverse problem to recover the skew-self-adjoint Dirac-type system from the generalized Weyl matrix function is treated in the paper. Sufficient conditions under which the unique solution of the inverse problem exists, are formulated in…

Classical Analysis and ODEs · Mathematics 2010-02-02 B. Fritzsche , B. Kirstein , A. L. Sakhnovich