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Related papers: Carleman estimates for geodesic X-ray transforms

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In this paper, we address a particular case of Calder\'on's (or conductivity) inverse problem in dimension two, namely the case of a homogeneous background containing a finite number of cavities (i.e. heterogeneities of infinitely high…

Analysis of PDEs · Mathematics 2018-03-12 Alexandre Munnier , Karim Ramdani

We consider planar directed last-passage percolation on the square lattice with general i.i.d. weights and study the geometry of the full set of semi-infinite geodesics in a typical realization of the random environment. The structure of…

Probability · Mathematics 2023-08-01 Christopher Janjigian , Firas Rassoul-Agha , Timo Seppäläinen

We study the geodesic X-ray transform on Cartan-Hadamard manifolds, and prove solenoidal injectivity of this transform acting on functions and tensor fields of any order. The functions are assumed to be exponentially decaying if the…

Differential Geometry · Mathematics 2019-09-06 Jere Lehtonen , Jesse Railo , Mikko Salo

Convex geometries are closure systems satisfying the anti-exchange axiom. Every finite convex geometry can be embedded into a convex geometry of finitely many points in an n-dimensional space equipped with a convex hull operator, by the…

Combinatorics · Mathematics 2016-09-02 Kira Adaricheva , Madina Bolat

We extend the application of Hamiltonian Monte Carlo to allow for sampling from probability distributions defined over symmetric or Hermitian positive definite matrices. To do so, we exploit the Riemannian structure induced by Cartan's…

Computation · Statistics 2016-12-28 Andrew Holbrook , Shiwei Lan , Alexander Vandenberg-Rodes , Babak Shahbaba

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

A vector field on a Riemannian manifold is called geodesic if its integral curves are reparametrized geodesics. We classify compact K\"ahler manifolds admitting nontrivial real-holomorphic geodesic gradient vector fields that satisfy an…

Differential Geometry · Mathematics 2023-09-12 Andrzej Derdzinski , Paolo Piccione

A new numerical method for X-ray tomography for a specific case of incomplete Radon data is proposed. Potential applications are in checking out bulky luggage in airports. This method is based on the analysis of the transport PDE governing…

Numerical Analysis · Mathematics 2019-05-01 Michael V. Klibanov , Loc H. Nguyen

We consider the anisotropic Calderon problem of recovering a conductivity matrix or a Riemannian metric from electrical boundary measurements in three and higher dimensions. In the earlier work \cite{DKSaU}, it was shown that a metric in a…

Analysis of PDEs · Mathematics 2014-05-13 David Dos Santos Ferreira , Yaroslav Kurylev , Matti Lassas , Mikko Salo

A 3D coefficient inverse problem for a hyperbolic equation with non-overdetermined data is considered. The forward problem is the Cauchy problems with the initial condition the delta function concentrated at a single plane (i.e. the plane…

Analysis of PDEs · Mathematics 2022-03-23 Michael V. Klibanov , Vladimir G. Romanov

We generalize the coset procedure of homogeneous spacetimes in (pseudo-)Riemannian geometry to non-Lorentzian geometries. These are manifolds endowed with nowhere vanishing invertible vielbeins that transform under local non-Lorentzian…

High Energy Physics - Theory · Physics 2018-08-08 Kevin T. Grosvenor , Jelle Hartong , Cynthia Keeler , Niels A. Obers

The orientability problem in real Gromov-Witten theory is one of the fundamental hurdles to enumerating real curves. In this paper, we describe topological conditions on the target manifold which ensure that the uncompactified moduli spaces…

Symplectic Geometry · Mathematics 2013-11-27 Penka Georgieva , Aleksey Zinger

In general relativity, Maxwell's equations are embedded in curved spacetime through the minimal prescription, but this could change if strong-gravity modifications are present. We show that with a nonminimal coupling between gravity and a…

General Relativity and Quantum Cosmology · Physics 2019-02-27 Lorenzo Annulli , Vitor Cardoso , Leonardo Gualtieri

In this paper the space of images is considered as a Riemannian manifold using the metamorphosis approach, where the underlying Riemannian metric simultaneously measures the cost of image transport and intensity variation. A robust and…

Numerical Analysis · Mathematics 2015-05-28 Benjamin Berkels , Alexander Effland , Martin Rumpf

This paper presents solutions to Einstein's equation -- and the numerical methods used to construct them -- that describe simple cosmological models on manifolds with compact non-orientable spatial slices. These solutions have been…

General Relativity and Quantum Cosmology · Physics 2026-04-28 Fan Zhang , Lee Lindblom

We revisit a little known theorem due to Beltrami, through which the integration of the geodesic equations of a curved manifold is accomplished by a method which, even if inspired by the Hamilton-Jacobi method, is purely geometric. The…

General Relativity and Quantum Cosmology · Physics 2008-04-03 Dino Boccaletti , Francesco Catoni , Roberto Cannata , Paolo Zampetti

Let $(M, g)$ be a complete Riemannian manifold without focal points and curvature bounded below. We prove that when the average of the sectional curvature in tangent planes along geodesics is negative and uniformly away from zero, then the…

Dynamical Systems · Mathematics 2023-04-24 Alexander Cantoral , Sergio Romaña

We consider the problem of developing a method to reconstruct a potential $q$ from the partial data Dirichlet-to-Neumann map for the Schr\"odinger equation $(-\Delta_g+q)u=0$ on a fixed admissible manifold $(M,g)$. If the part of the…

Analysis of PDEs · Mathematics 2015-11-11 Yernat M Assylbekov

This paper addresses the inverse scattering problem in the domain Omega. The input data, measured outside Omega, involve the waves generated by the interaction of plane waves with various directions and unknown scatterers fully occluded…

Numerical Analysis · Mathematics 2024-06-25 Phuong M. Nguyen , Loc H. Nguyen , Huong T. T. Vu

We define the notion of a smooth pseudo-Riemannian algebraic variety $(X,g)$ over a field $k$ of characteristic $0$, which is an algebraic analogue of the notion of Riemannian manifold and we study, from a model-theoretic perspective, the…

Differential Geometry · Mathematics 2017-03-09 Remi Jaoui