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We show that the geodesic ray transform is injective on scalar functions on spherically symmetric reversible Finsler manifolds where the Finsler norm satisfies a Herglotz condition. We use angular Fourier series to reduce the injectivity…

微分几何 · 数学 2022-12-06 Joonas Ilmavirta , Keijo Mönkkönen

We prove that the geodesic X-ray transform is injective on scalar functions and (solenoidally) on one-forms on simple Riemannian manifolds $(M,g)$ with $g \in C^{1,1}$. In addition to a proof, we produce a redefinition of simplicity that is…

微分几何 · 数学 2023-04-12 Joonas Ilmavirta , Antti Kykkänen

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…

微分几何 · 数学 2024-02-15 Joonas Ilmavirta , Antti Kykkänen

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…

偏微分方程分析 · 数学 2013-06-13 Mark Hubenthal

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…

微分几何 · 数学 2016-06-21 Joonas Ilmavirta

This PhD thesis studies the broken ray transform, a generalization of the geodesic X-ray transform where geodesics are replaced with broken rays that reflect on a part of the boundary. The fundamental question is whether this transform is…

微分几何 · 数学 2014-09-29 Joonas Ilmavirta

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…

偏微分方程分析 · 数学 2016-07-28 Mark Hubenthal

In this paper we formulate and prove a gauge equivalence for unitary connections and skew-Hermitian Higgs fields of suitable regularity that are mapped to the same function under the non-abelian X-ray transform on nontrapping asymptotically…

微分几何 · 数学 2025-02-20 Haim Grebnev

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…

微分几何 · 数学 2017-07-06 Joonas Ilmavirta , Gunther Uhlmann

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…

偏微分方程分析 · 数学 2023-09-25 Joonas Ilmavirta , Antti Kykkänen , Kelvin Lam

We consider the boundary rigidity problem for asymptotically hyperbolic manifolds. We show injectivity of the X-ray transform in several cases and consider the non-linear inverse problem which consists of recovering a metric from boundary…

微分几何 · 数学 2017-09-18 C. Robin Graham , Colin Guillarmou , Plamen Stefanov , Gunther Uhlmann

A method of approximating the inverse Radon transform on the plane by integrating against a smooth kernel is investigated. For piecewise smooth integrable functions, convergence theorems are proven and Gibbs phenomena are ruled out.…

数值分析 · 数学 2019-10-22 Shavkat Alimov , Joseph David , Alexander Nolte , Julie Sherman

Consider a compact Riemannian manifold of dimension $\geq 3$ with strictly convex boundary, such that the manifold admits a strictly convex function. We show that the attenuated ray transform in the presence of an arbitrary connection and…

微分几何 · 数学 2018-06-05 Gabriel P. Paternain , Mikko Salo , Gunther Uhlmann , Hanming Zhou

In dimensions $\geq 3$, we prove that the X-ray transform of symmetric tensors of arbitrary degree is generically injective with respect to the metric on closed Anosov manifolds and on manifolds with spherical strictly convex boundary, no…

偏微分方程分析 · 数学 2024-01-25 Mihajlo Cekić , Thibault Lefeuvre

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…

偏微分方程分析 · 数学 2023-05-10 Ali Feizmohammadi , Joonas Ilmavirta , Lauri Oksanen

This paper settles the question of injectivity of the non-Abelian X-ray transform on simple surfaces for the general linear group of invertible complex matrices. The main idea is to use a factorization theorem for Loop Groups to reduce to…

微分几何 · 数学 2022-01-27 Gabriel P. Paternain , Mikko Salo

Generalized Abel equations have been employed in the recent literature to invert Radon transforms which arise in a number of important imaging applications, including Compton Scatter Tomography (CST), Ultrasound Reflection Tomography (URT),…

泛函分析 · 数学 2023-06-16 James W. Webber

We prove for the first time a pointwise lower estimate of the normal injectivity radius of an embedded hypersurface in an arbitrary Riemannian manifold. Main applications include: (i) a pointwise lower estimate of the graphing radius of a…

微分几何 · 数学 2025-11-26 Sebastian Boldt , Batu Güneysu , Stefano Pigola

We consider the X-ray transform in a projective space over a finite field. It is well known (after E. Bolker) that this transform is injective. We formulate an analog of I.M. Gelfand's admissibility problem for the Radon transform, which…

度量几何 · 数学 2017-07-26 David V. Feldman , Eric L. Grinberg

It has been shown in [Pa1] that on a simple, compact Riemannian 2-manifold the attenuated geodesic ray transform, with attenuation given by a connection and Higgs field, is injective on functions and 1-forms modulo the natural obstruction.…

微分几何 · 数学 2013-03-29 Gareth Ainsworth
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