English
Related papers

Related papers: Singularly Weighted X-ray Tensor Tomography

200 papers

Atmospheric tomography, the problem of reconstructing atmospheric turbulence profiles from wavefront sensor measurements, is an integral part of many adaptive optics systems used for enhancing the image quality of ground-based telescopes.…

Numerical Analysis · Mathematics 2025-02-06 Lukas Weissinger , Simon Hubmer , Bernadett Stadler , Ronny Ramlau

Based on direct integrals, a framework allowing to integrate a parametrised family of reproducing kernels with respect to some measure on the parameter space is developed. By pointwise integration, one obtains again a reproducing kernel…

Functional Analysis · Mathematics 2012-02-21 Thomas Hotz , Fabian J. E. Telschow

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

The squared singular values of the product of $M$ complex Ginibre matrices form a biorthogonal ensemble, and thus their distribution is fully determined by a correlation kernel. The kernel permits a hard edge scaling to a form specified in…

Classical Analysis and ODEs · Mathematics 2016-05-04 N. S. Witte , P. J. Forrester

We exhibit for all positive integers r, an explicit cellular structure for the endomorphism algebra of the r'th tensor power of an integral form of the Weyl module with highest weight d of the quantised enveloping algebra of sl2. When q is…

Group Theory · Mathematics 2013-03-06 H. H. Andersen , G. I. Lehrer , R. B. Zhang

In this work, we prove a new decomposition result for rank $m$ symmetric tensor fields which generalizes the well known solenoidal and potential decomposition of tensor fields. This decomposition is then used to describe the kernel and to…

Analysis of PDEs · Mathematics 2020-06-24 Rohit Kumar Mishra , Suman Kumar Sahoo

A method to reconstruct weakly anisotropic inhomogeneous dielectric tensors inside a transparent medium is proposed. The mathematical theory of Integral Geometry is cast into a workable framework which allows the full determination of…

Optics · Physics 2009-11-10 Hanno Hammer , William R. B. Lionheart

This work aims to prove that the classical Gaussian kernel, when defined on a non-Euclidean symmetric space, is never positive-definite for any choice of parameter. To achieve this goal, the paper develops new geometric and analytical…

Machine Learning · Computer Science 2024-09-09 Nathael Da Costa , Cyrus Mostajeran , Juan-Pablo Ortega , Salem Said

We analyse the highest weight representations of the N=1 Ramond algebra and show that their structure is richer than previously suggested in the literature. In particular, we show that certain Verma modules over the N=1 Ramond algebra…

High Energy Physics - Theory · Physics 2009-10-31 Matthias Doerrzapf

Topological transforms are parametrized families of topological invariants, which, by analogy with transforms in signal processing, are much more discriminative than single measurements. The first two topological transforms to be defined…

Algebraic Topology · Mathematics 2020-04-01 Clément Maria , Steve Oudot , Elchanan Solomon

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

We identify a sharp geometric threshold governing the infrared spectral behavior of the spatial Lichnerowicz operator on asymptotically flat three-dimensional manifolds. Let $(M,g)$ be asymptotically flat and let $L=\Delta_L$ denote the…

General Relativity and Quantum Cosmology · Physics 2026-02-23 Michael Wilson

For type IIB supergravity with a running axio-dilaton, we construct bulk solutions which admit a cosmological background metric of Friedmann-Robertson-Walker type. These solutions include both a dark radiation term in the bulk as well as a…

High Energy Physics - Theory · Physics 2011-08-09 Johanna Erdmenger , Kazuo Ghoroku , Rene Meyer

The X-ray transform is one of the most fundamental integral operators in image processing and reconstruction. In this article, we revisit the formalism of the X-ray transform by considering it as an operator between Reproducing Kernel…

Functional Analysis · Mathematics 2024-06-26 Ho Yun , Victor M. Panaretos

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

In nuclear arms control and disarmament processes, it is crucial to determine whether an object is a nuclear weapon or not without revealing sensitive information about it. At the MIT: Laboratory for Nuclear Security and Policy, such a…

Numerical Analysis · Mathematics 2026-03-20 Christopher Fichtlscherer , R. Scott Kemp , Christina Brandt

In this article, we study a restricted mixed ray transform acting on second-order tensor fields in 3-dimensional Euclidean space and prove the invertibility of this integral transform using microlocal techniques. Here, the mixed ray…

Analysis of PDEs · Mathematics 2024-09-17 Chandni Thakkar

The Riesz transform of $u$ : $\mathcal{S}(\mathbb{R}^n) \rightarrow \mathcal{S'}(\mathbb{R}^n)$ is defined as a convolution by a singular kernel, and can be conveniently expressed using the Fourier Transform and a simple multiplier. We…

Numerical Analysis · Mathematics 2022-09-05 Mathias Perrin , Frederic Gruy

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 infinite weighted graphs with view to \textquotedblleft limits at infinity,\textquotedblright or boundaries at infinity. Examples of such weighted graphs arise in infinite (in practice, that means \textquotedblleft…

Mathematical Physics · Physics 2015-05-13 Palle E. T. Jorgensen