English
Related papers

Related papers: Microlocal analysis of a restricted ray transform …

200 papers

We consider the Radon transform along lines in an $n$ dimensional vector space over the two element field. It is well known that this transform is injective and highly overdetermined. We classify the minimal collections of lines for which…

Combinatorics · Mathematics 2019-07-10 Eric L. Grinberg

We prove solenoidal injectivity for the geodesic X-ray transform of tensor fields on simple Riemannian manifolds with $C^{1,1}$ metrics and non-positive sectional curvature. The proof of the result rests on Pestov energy estimates for a…

Differential Geometry · Mathematics 2024-02-15 Joonas Ilmavirta , Antti Kykkänen

Consider a compact Riemannian manifold in dimension $n$ with strictly convex boundary. We show the local invertibility near a boundary point of the transverse ray transform of $2$ tensors for $n\geq 3$ and the mixed ray transform of $2+2$…

Differential Geometry · Mathematics 2024-02-21 Gunther Uhlmann , Jian Zhai

We propose a theory of eigenvalues, eigenvectors, singular values, and singular vectors for tensors based on a constrained variational approach much like the Rayleigh quotient for symmetric matrix eigenvalues. These notions are particularly…

Spectral Theory · Mathematics 2007-05-23 Lek-Heng Lim

We propose a thorough analysis of the tensor tomography problem on the Euclidean unit disk parameterized in fan-beam coordinates. This includes, for the inversion of the Radon transform over functions, using another range characterization…

Analysis of PDEs · Mathematics 2016-03-25 Francois Monard

We study the extent to which Milne-Eddington inversions are able to retrieve and characterize the magnetic landscape of the solar poles from observations by the spectropolarimeter onboard Hinode. In particular, we evaluate whether a…

Solar and Stellar Astrophysics · Physics 2023-07-05 Rebecca Centeno , Ivan Milić , Matthias Rempel , Nariaki V. Nitta , Xudong Sun

Currently, theory of ray transforms of vector and tensor fields is well developed, but the Radon transforms of such fields have not been fully analyzed. We thus consider linearly weighted and unweighted longitudinal and transversal Radon…

Analysis of PDEs · Mathematics 2023-05-24 L. Kunyansky , E. McDugald , B. Shearer

This paper concerns the reconstruction of a complex-valued anisotropic tensor $\gamma=\sigma+\i\omega\varepsilon$ from knowledge of several internal magnetic fields $H$, where $H$ satisfies the anisotropic Maxwell system on a bounded domain…

Analysis of PDEs · Mathematics 2013-09-10 Chenxi Guo , Guillaume Bal

This paper is concerned with an inverse transmission problem for recovering the shape of a penetrable rectangular grating sitting on a perfectly conducting plate. We consider a general transmission problem with the coefficient \lambda\neq 1…

Analysis of PDEs · Mathematics 2023-04-24 Jianli Xiang , Guanghui Hu

We study the broken ray transform on $n$-dimensional Euclidean domains where the reflecting parts of the boundary are flat and establish injectivity and stability under certain conditions. Given a subset $E$ of the boundary $\partial…

Analysis of PDEs · Mathematics 2016-07-28 Mark Hubenthal

This article presents the numerical verification and validation of several inversion algorithms for V-line transforms (VLTs) acting on symmetric 2-tensor fields in the plane. The analysis of these transforms and the theoretical foundation…

Numerical Analysis · Mathematics 2024-07-04 Gaik Ambartsoumian , Rohit Kumar Mishra , Indrani Zamindar

We develop an algorithm for reconstruction of elastic strain fields from their Longitudinal Ray Transform (LRT) in either two or three dimensions. In general, the LRT only determines the solenoidal part of a symmetric tensor field, but…

Numerical Analysis · Mathematics 2024-08-21 Chris Wensrich , Sean Holman , William Lionheart , Matias Courdurier , Anna Polyakova , Ivan Svetov , Ty Doubikin

This paper is the first in a series of two articles whose aim is to extend a recent result of Guillarmou-Lefeuvre on the local rigidity of the marked length spectrum from the case of compact negatively-curved Riemannian manifolds to the…

Differential Geometry · Mathematics 2020-11-30 Yannick Guedes Bonthonneau , Thibault Lefeuvre

Inversion of potential field data is a central technique of remote sensing in physics, geophysics, neuroscience and medical imaging. In spite of intense research, uniqueness theorems for potential-field inversion are scarce. Applied studies…

Geophysics · Physics 2021-01-07 Karl Fabian , Lennart V. de Groot

We characterize the kernel of the mixed ray transform on simple $2$-dimensional Riemannian manifolds, that is, on simple surfaces for tensors of any order.

Differential Geometry · Mathematics 2018-08-07 Maarten V. de Hoop , Teemu Saksala , Jian Zhai

Polarized magnetic dipole (M1) emission lines provide important diagnostics for the magnetic field dominating the evolution of the solar corona. This paper advances a multi-line technique using specific combinations of M1 lines to infer the…

Solar and Stellar Astrophysics · Physics 2020-02-12 Gabriel I. Dima , Thomas A. Schad

We study transition form factors for radiative and rare semi-leptonic B-meson decays into light pseudoscalar or vector mesons, combining theoretical constraints and phenomenological information from Lattice QCD, light-cone sum rules, and…

High Energy Physics - Phenomenology · Physics 2015-03-14 Aoife Bharucha , Thorsten Feldmann , Michael Wick

We consider the problem of determination of a magnetic field from three dimensional polarimetric neutron tomography data. We see that this is an example of a non-Abelian ray transform and that the problem has a globally unique solution for…

Analysis of PDEs · Mathematics 2019-10-21 Naeem M. Desai , William R. B. Lionheart , Morten Sales , Markus Strobl , Søren Schmidt

We reduce the broken ray transform on some Riemannian manifolds (with corners) to the geodesic ray transform on another manifold, which is obtained from the original one by reflection. We give examples of this idea and present injectivity…

Differential Geometry · Mathematics 2016-06-21 Joonas Ilmavirta

We prove the local invertibility, up to potential fields, and stability of the geodesic X-ray transform on tensor fields of order 1 and 2 near a strictly convex boundary point, on manifolds with boundary of dimension n>=3. We also present…

Differential Geometry · Mathematics 2014-10-21 Plamen Stefanov , Gunther Uhlmann , András Vasy