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Weighted V-line transforms map a symmetric tensor field of order $m\ge0$ to a linear combination of certain integrals of those fields along two rays emanating from the same vertex. A significant focus of current research in integral…

Classical Analysis and ODEs · Mathematics 2025-11-05 Gaik Ambartsoumian , Rohit Kumar Mishra , Indrani Zamindar

A unique inversion of the exponential X-ray transform of some class of symmetric 2-tensor field in a two dimensional strictly convex set is considered. The approach to inversion is based on the Cauchy problem for a Beltrami-like equation…

Analysis of PDEs · Mathematics 2024-12-06 David Omogbhe

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

The two-dimensional (2D) orientation field transform has been proved to be effective at enhancing 2D contours and curves in images by means of top-down processing. It, however, has no counterpart in three-dimensional (3D) images due to the…

Computer Vision and Pattern Recognition · Computer Science 2020-10-06 Wai-Tsun Yeung , Xiaohao Cai , Zizhen Liang , Byung-Ho Kang

We consider Calderon's inverse problem with partial data in dimensions $n \geq 3$. If the inaccessible part of the boundary satisfies a (conformal) flatness condition in one direction, we show that this problem reduces to the invertibility…

Analysis of PDEs · Mathematics 2016-01-20 Carlos E. Kenig , Mikko Salo

Tetrahedral frame fields have applications to certain classes of nematic liquid crystals and frustrated media. We consider the problem of constructing a tetrahedral frame field in three dimensional domains in which the boundary normal…

Analysis of PDEs · Mathematics 2023-04-19 Dmitry Golovaty , Matthias Kurzke , Jose Alberto Montero , Daniel Spirn

We prove that the geodesic X-ray transform is injective on $L^2$ when the Riemannian metric is simple but the metric tensor is only finitely differentiable. The number of derivatives needed depends explicitly on dimension, and in dimension…

Analysis of PDEs · Mathematics 2023-09-25 Joonas Ilmavirta , Antti Kykkänen , Kelvin Lam

Many machine learning problems involve regressing variables on a non-Euclidean manifold -- e.g. a discrete probability distribution, or the 6D pose of an object. One way to tackle these problems through gradient-based learning is to use a…

Computer Vision and Pattern Recognition · Computer Science 2021-10-14 Romain Brégier

We present a reconstruction method that stably recovers the real valued, symmetric tensors compactly supported in the Euclidean plane, from knowledge of their attenuated momenta ray transform. The problem is recast as an inverse boundary…

Analysis of PDEs · Mathematics 2024-05-09 Hiroshi Fujiwara , David Omogbhe , Kamran Sadiq , Alexandru Tamasan

Optics related to non-Euclidean geometry has been attracting growing interest for emerged novel phenomena and the analog for general relativity, while most studies are limited to the free space on rotationally-symmetric surfaces. In this…

This article studies the inverse problem of recovering a vector field supported in $\mathbb{D}_R$, the disk of radius $R$ centered at the origin, through a set of generalized broken ray/V-line transforms, namely longitudinal and transverse…

Classical Analysis and ODEs · Mathematics 2024-04-22 Rahul Bhardwaj , Rohit Kumar Mishra , Manmohan Vashisth

Assume (M,g,\Omega) is a closed, oriented Riemannian surface equipped with an Anosov magnetic flow. We establish certain results on the surjectivity of the adjoint of the magnetic ray transform, and use these to prove the injectivity of the…

Differential Geometry · Mathematics 2013-11-06 Gareth Ainsworth

We present a deep learning-based computational algorithm for inversion of circular Radon transforms in the partial radial setup, arising in photoacoustic tomography. We first demonstrate that the truncated singular value decomposition-based…

Machine Learning · Computer Science 2023-08-29 Deep Ray , Souvik Roy

Electromagnetic metasurfaces have attracted significant interest recently due to their low profile and advantageous applications. Practically, many metasurface designs start with a set of constraints for the radiated far-field, such as…

Materials Science · Physics 2022-04-04 Stewart Pearson , Parinaz Naseri , Sean V. Hum

The X-ray transform on the periodic slab $[0,1]\times\mathbb T^n$, $n\geq0$, has a non-trivial kernel due to the symmetry of the manifold and presence of trapped geodesics. For tensor fields gauge freedom increases the kernel further, and…

Differential Geometry · Mathematics 2017-07-06 Joonas Ilmavirta , Gunther Uhlmann

We study a particular broken ray transform on the Euclidean unit square and establish injectivity and stability for $C_{0}^{2}$ perturbations of the constant unit weight. Given an open subset $E$ of the boundary, we measure the attenuation…

Analysis of PDEs · Mathematics 2013-06-13 Mark Hubenthal

In this work, we study a set of generalized Radon transforms over symmetric $m$-tensor fields in $\mathbb{R}^n$. The longitudinal/transversal Radon transform and corresponding weighted integral transforms for symmetric $m$-tensor field are…

Analysis of PDEs · Mathematics 2025-02-05 Anuj Abhishek , Rohit Kumar Mishra , Chandni Thakkar

Given a Lorentzian manifold, the light ray transform of a function is its integrals along null geodesics. This paper is concerned with the injectivity of the light ray transform on functions and tensors, up to the natural gauge for the…

Analysis of PDEs · Mathematics 2023-05-10 Ali Feizmohammadi , Joonas Ilmavirta , Lauri Oksanen

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 capable of imaging a three-dimensional object given a collection of two-dimensional images of that object that are significantly influenced by the curvature of the Ewald sphere. These two-dimensional images cannot be…

Instrumentation and Detectors · Physics 2021-03-02 J. P. J. Chen , K. E. Schmidt , J. C. H. Spence , R. A. Kirian