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We provide conditions under which a Riemann surface $X$ is the asymptotic boundary of a convex co-compact hyperbolic manifold, homeomorphic to a handlebody, of negative renormalized volume. We prove that this is the case when there are on…

Differential Geometry · Mathematics 2025-08-18 Tommaso Cremaschi , Viola Giovannini , Jean-Marc Schlenker

X-ray interaction with matter is an energy-dependent process that is contingent on the atomic structure of the constituent material elements. The most advanced models to capture this relationship currently rely on Monte Carlo (MC)…

Machine Learning · Computer Science 2023-07-11 Raziye Kubra Kumrular , Thomas Blumensath

We consider the inverse problem of recovering a potential from the Dirichlet to Neumann map at a large fixed frequency on certain Riemannian manifolds. We extend the earlier result of [G. Uhlmann and Y. Wang, arXiv:2104.03477] to the case…

Analysis of PDEs · Mathematics 2023-09-01 Shiqi Ma , Suman Kumar Sahoo , Mikko Salo

An asymptotic approach for a Schroedinger type equation with non selfadjoint Hamiltonian of a special type in the case of two close degeneracy (turning) points is developed. Both real and complex degeneracy points are treated by a method of…

Mathematical Physics · Physics 2021-07-20 Ignat Fialkovsky , Maria Perel

This paper initiates a systematic development of a theory of non-commutative optimization. It aims to unify and generalize a growing body of work from the past few years which developed and analyzed algorithms for natural geodesically…

Optimization and Control · Mathematics 2021-07-28 Peter Bürgisser , Cole Franks , Ankit Garg , Rafael Oliveira , Michael Walter , Avi Wigderson

Textures in images can often be well modeled using self-similar processes while they may at the same time display anisotropy. The present contribution thus aims at studying jointly selfsimilarity and anisotropy by focusing on a specific…

Data Analysis, Statistics and Probability · Physics 2015-06-16 S. G. Roux , M. Clausel , B. Vedel , S. Jaffard , P. Abry

Given an m-dimensional compact submanifold $\mathbf{M}$ of Euclidean space $\mathbf{R}^s$, the concept of mean location of a distribution, related to mean or expected vector, is generalized to more general $\mathbf{R}^s$-valued functionals…

Statistics Theory · Mathematics 2007-08-07 Harrie Hendriks , Zinoviy Landsman

Transport-based metrics and related embeddings (transforms) have recently been used to model signal classes where nonlinear structures or variations are present. In this paper, we study the geodesic properties of time series data with a…

Machine Learning · Computer Science 2022-06-14 Shiying Li , Abu Hasnat Mohammad Rubaiyat , Gustavo K. Rohde

Motivated by the relative differential geometry, where the Euclidean normal vector of hypersurfaces is generalized by a relative normalization, we introduce anisotropic area measures of convex bodies, constructed with respect to a gauge…

Metric Geometry · Mathematics 2025-06-17 Rolf Schneider

In this article we consider the anisotropic Calderon problem and related inverse problems. The approach is based on limiting Carleman weights, introduced in Kenig-Sjoestrand-Uhlmann (Ann. of Math. 2007) in the Euclidean case. We…

Analysis of PDEs · Mathematics 2015-05-13 D. Dos Santos Ferreira , C. E. Kenig , M. Salo , G. Uhlmann

The article surveys inverse problems related to the twisted geodesic flows on Riemannian manifolds with boundary, focusing on the generalized ray transforms, tensor tomography, and rigidity problems. The twisted geodesic flow generalizes…

Differential Geometry · Mathematics 2025-08-12 Shubham R. Jathar , Jesse Railo

We describe the inverse image of the Riemannian exponential map at a basepoint of a compact symmetric space as the disjoint union of so called focal orbits through a maximal torus. These are orbits of a subgroup of the isotropy group acting…

Differential Geometry · Mathematics 2024-04-03 Lucas Seco , Mauro Patrão

We verify the 3-dimensional Glassey conjecture on asymptotically flat manifolds $(R^{1+3}, g)$, where the metric $g$ is certain small space-time perturbation of the flat metric, as well as the nontrapping asymptotically Euclidean manifolds.…

Analysis of PDEs · Mathematics 2015-02-13 Chengbo Wang

The nonlinear equations describing all the nonsingular pencils of metrics of constant Riemannian curvature are derived and the integrability of these nonlinear equations by the method of inverse scattering problem is proved. It is proved…

Differential Geometry · Mathematics 2010-01-04 O. I. Mokhov

This paper addresses the topic of robust Bayesian compressed sensing over finite fields. For stationary and ergodic sources, it provides asymptotic (with the size of the vector to estimate) necessary and sufficient conditions on the number…

Information Theory · Computer Science 2014-01-20 Wenjie Li , Francesca Bassi , Michel Kieffer

Shear-free or asymptotically shear-free null geodesic congruences possess a large number of fascinating geometric properties and to be closely related, in the context of general relativity, to a variety of physically significant affects. It…

General Relativity and Quantum Cosmology · Physics 2016-11-23 T. M. Adamo , E. T. Newman , C. N. Kozameh

We show the flexibility of the metric entropy and obtain additional restrictions on the topological entropy of geodesic flow on closed surfaces of negative Euler characteristic with smooth non-positively curved Riemannian metrics with fixed…

Dynamical Systems · Mathematics 2020-08-07 Thomas Barthelmé , Alena Erchenko

We consider the broken ray transform on Riemann surfaces in the presence of an obstacle, following earlier work of Mukhometov. If the surface has nonpositive curvature and the obstacle is strictly convex, we show that a function is…

Differential Geometry · Mathematics 2016-06-21 Joonas Ilmavirta , Mikko Salo

We study integral transforms mapping a function on the Euclidean space to the family of its integration on some hypersurfaces, that is, a function of hypersurfaces. The hypersurfaces are given by the graphs of functions with fixed axes of…

Classical Analysis and ODEs · Mathematics 2020-06-08 Hiroyuki Chihara

A sequence of distinct closed surfaces in a hyperbolic 3-manifold M is asymptotically geodesic if their principal curvatures tend uniformly to zero. When M has finite volume, we show such sequences are always asymptotically dense in the…

Differential Geometry · Mathematics 2025-02-25 Fernando Al Assal , Ben Lowe