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相关论文: Microlocal analysis of the X-ray transform in non-…

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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

In this article, we study the properties of the geodesic X-ray transform for asymptotically Euclidean or conic Riemannian metrics and show injectivity under non-trapping and no conjugate point assumptions. We also define a notion of lens…

微分几何 · 数学 2021-02-09 Colin Guillarmou , Matti Lassas , Leo Tzou

We show injectivity of the geodesic X-ray transform on piecewise constant functions when the transform is weighted by a continuous matrix weight. The manifold is assumed to be compact and nontrapping of any dimension, and in dimension three…

微分几何 · 数学 2020-10-23 Joonas Ilmavirta , Jesse Railo

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 derive reconstruction formulas for a family of geodesic ray transforms with connection, defined on simple Riemannian surfaces. Such formulas provide injectivity of such all transforms in a neighbourhood of constant curvature metrics and…

微分几何 · 数学 2017-09-22 François Monard , Gabriel P. Paternain

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

We study the microlocal properties of the geodesic X-ray transform $\mathcal{X}$ on a manifold with boundary allowing the presence of conjugate points. Assuming that there are no self-intersecting geodesics and all conjugate pairs are…

微分几何 · 数学 2015-02-24 Sean Holman , Gunther Uhlmann

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

In this paper we show the invertibility of the geodesic X-ray transform on one forms and 2-tensors on asymptotically conic manifolds, up to the natural obstruction, allowing existence of certain kinds of conjugate points. We use the 1-cusp…

微分几何 · 数学 2022-12-06 Qiuye Jia , András Vasy

We initiate the study of X-ray tomography on sub-Riemannian manifolds, for which the Heisenberg group exhibits the simplest nontrivial example. With the language of the group Fourier Transform, we prove an operator-valued incarnation of the…

微分几何 · 数学 2020-10-22 Steven Flynn

We study the geodesic X-ray transform $X$ on compact Riemannian surfaces with conjugate points. Regardless of the type of the conjugate points, we show that we cannot recover the singularities and therefore, this transform is always…

微分几何 · 数学 2015-05-20 François Monard , Plamen Stefanov , Gunther Uhlmann

Let $(M,g)$ be a simple Riemannian manifold. Under the assumption that the metric $g$ is real-analytic, it is shown that if the geodesic ray transform of a function $f\in L^{2}(M)$ vanishes on an appropriate open set of geodesics, then…

微分几何 · 数学 2008-03-29 V. Krishnan

We consider the attenuated geodesic ray transform defined on pairs of symmetric $2$-tensors and $1$-forms on a simple Riemannian manifold. We prove injectivity and stability results for a class of generic simple metrics and attenuations…

偏微分方程分析 · 数学 2018-09-18 Yernat M. Assylbekov

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

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

Under real-analytic assumptions on decoder-only Transformers, recent work shows that the map from discrete prompts to last-token hidden states is generically injective on finite prompt sets. We refine this picture: for each layer $\ell$ we…

机器学习 · 计算机科学 2025-11-20 Mikael von Strauss

We prove injectivity and a support theorem for the X-ray transform on $2$-step nilpotent Lie groups with many totally geodesic $2$-dimensional flats. The result follows from a general reduction principle for manifolds with uniformly…

微分几何 · 数学 2016-01-19 Norbert Peyerimhoff , Evangelia Samiou

We present a numerical implementation of the geodesic ray transform and its inversion over functions and solenoidal vector fields on two-dimensional Riemannian manifolds. For each problem, inversion formulas previously derived in…

微分几何 · 数学 2014-04-17 François Monard

We study the geodesic X-ray transform $I_\Gamma$ of tensor fields on a compact Riemannian manifold $M$ with non-necessarily convex boundary and with possible conjugate points. We assume that $I_\Gamma$ is known for geodesics belonging to an…

微分几何 · 数学 2007-05-23 Plamen Stefanov , Gunther Uhlmann

We give a detailed microlocal study of X-ray transforms over geodesics-like families of curves with conjugate points of fold type. We show that the normal operator is the sum of a pseudodifferential operator and a Fourier integral operator.…

微分几何 · 数学 2010-04-08 Plamen Stefanov , Gunther Uhlmann
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