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Related papers: Functions of constant geodesic X-ray transform

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For every proper geodesic space $X$ we introduce its quasi-geometric boundary $\partial_{QG}X$ with the following properties: 1. Every geodesic ray $g$ in $X$ converges to a point of the boundary $\partial_{QG}X$ and for every point $p$ in…

Metric Geometry · Mathematics 2022-09-13 Jerzy Dydak , Hussain Rashed

The purpose of this paper is to provide a set of sufficient conditions so that the normalized form of the Fox-Wright functions have certain geometric properties like close-to-convexity, univalency, convexity and starlikeness inside the unit…

Classical Analysis and ODEs · Mathematics 2019-03-14 Khaled Mehrez

In this paper we have generalized the notion of $\lambda$-radial contraction in complete Riemannian manifold and developed the concept of $p^\lambda$-convex function. We have also given a counter example proving the fact that in general…

Differential Geometry · Mathematics 2019-07-08 Absos Ali Shaikh , Chandan Kumar Mondal , Akhlad Iqbal

Convexity and convex functions play an important role in theoretical physics. To initiate a study of the possible uses of convex functions in General Relativity, we discuss the consequences of a spacetime $(M,g_{\mu \nu})$ or an initial…

General Relativity and Quantum Cosmology · Physics 2009-10-07 Gary W. Gibbons , Akihiro Ishibashi

Convexity and convex functions play an important role in theoretical physics. To initiate a study of the possible uses of convex functions in General Relativity, we discuss the consequences of a spacetime $(M,g_{\mu \nu})$ or an initial…

Differential Geometry · Mathematics 2017-02-21 Gary W. Gibbons , Akihiro Ishibashi

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…

Differential Geometry · Mathematics 2008-03-29 V. Krishnan

We consider in this paper an area functional defined on submanifolds of fixed degree immersed into a graded manifold equipped with a Riemannian metric. Since the expression of this area depends on the degree, not all variations are…

Differential Geometry · Mathematics 2021-12-21 Giovanna Citti , Gianmarco Giovannardi , Manuel Ritoré

It is shown that a real-valued formal meromorphic function on a formal generic submanifold of finite Kohn-Bloom-Graham type is necessarily constant.

Complex Variables · Mathematics 2008-03-17 Robert Juhlin , Bernhard Lamel , Francine Meylan

We prove that any piece of a rotational hypersurface with prescribed mean curvature function in a Euclidean space can be uniquely extended infinitely, which generalizes the results by Euler and Delaunay for surfaces of revolution with…

Differential Geometry · Mathematics 2013-07-12 Katsuei Kenmotsu , Takeyuki Nagasawa

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…

Differential Geometry · Mathematics 2014-04-17 François Monard

In this article we study the shape of a compact surface of constant mean curvature of Euclidean space whose boundary is contained in a round sphere. We consider the case that the boundary is prescribed or that the surface meets the sphere…

Differential Geometry · Mathematics 2014-10-22 Rafael López , Juncheol Pyo

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…

Differential Geometry · Mathematics 2007-05-23 Plamen Stefanov , Gunther Uhlmann

It is shown that a smooth n dimensional manifold with a boundary in R^n admits a Boolean representation in terms of closed half spaces defined by the tangent hyperplanes at the points on its boundary. A similar result is established for…

Classical Analysis and ODEs · Mathematics 2007-05-23 Sergei Ovchinnikov

We study the boundary and lens rigidity problems on domains without assuming the convexity of the boundary. We show that such rigidities hold when the domain is a simply connected compact Riemannian surface without conjugate points. For the…

Differential Geometry · Mathematics 2021-03-24 Colin Guillarmou , Marco Mazzucchelli , Leo Tzou

We study the problem of proper discretizing and sampling issues related to geodesic X-ray transforms on simple surfaces, and illustrate the theory on simple geodesic disks of constant curvature. Given a notion of band limit on a function,…

Analysis of PDEs · Mathematics 2022-12-07 François Monard , Plamen Stefanov

The convolution of a function with an isotropic Gaussian appears in many contexts such as differential equations, computer vision, signal processing, and numerical optimization. Although this convolution does not always have a closed form…

Classical Analysis and ODEs · Mathematics 2016-03-08 Hossein Mobahi

Using the theory of geodesics on surfaces of revolution, we introduce the period function. We use this as our main tool in showing that any two-dimensional orbifold of revolution homeomorphic to S^2 must contain an infinite number of…

Differential Geometry · Mathematics 2007-05-23 Joseph E. Borzellino , Christopher R. Jordan-Squire , Gregory C. Petrics , D. Mark Sullivan

We describe the range of a restricted spherical mean transform, which sends a function supported inside a closed ball in a hyperbolic space to its mean values on the geodesics spheres centered at the boundary of the ball. The description…

Differential Geometry · Mathematics 2011-09-28 Linh V. Nguyen

For $L$-functions attached to automorphic representations of unitary groups $U_{n+1}\times U_n$, we establish a subconvex bound valid in certain horizontal aspects, where the set of ramified places is allowed to vary.

Number Theory · Mathematics 2023-12-18 Yueke Hu , Paul D. Nelson

A relatively polynomially convex subset $V$ of a domain $\Omega$ has the extension property if for every polynomial $p$ there is a bounded holomorphic function $\phi$ on $\Omega$ that agrees with $p$ on $V$ and whose $H^\infty$ norm on…

Complex Variables · Mathematics 2017-04-13 Lukasz Kosinski , John McCarthy