English
Related papers

Related papers: No return to convexity

200 papers

We consider the structure of divergence-free vector measures on the plane. We show that such measures can be decomposed into measures induced by closed simple curves. More generally, we show that if the divergence of a planar vector-valued…

Analysis of PDEs · Mathematics 2020-11-25 Paolo Bonicatto , Nikolay A. Gusev

We construct two particular solutions of the full Euler system which emanate from the same initial data. Our aim is to show that the convex combination of these two solutions form a measure-valued solution which may not be approximated by a…

Analysis of PDEs · Mathematics 2020-10-01 Václav Mácha , Emil Wiedemann

It is well-known that the cross covariogram of two convex bodies in n dimensions is 1/n-concave on its support. This paper provides conditions for strict 1/n-concavity in dimension n>1, and an analysis of how it can fail. Among the…

Metric Geometry · Mathematics 2025-08-07 Gabriele Bianchi , Almut Burchard , Lawrence Lin

This article is a survey of recent results on slicing inequalities for convex bodies. The focus is on the setting of arbitrary measures in place of volume.

Metric Geometry · Mathematics 2015-11-18 Alexander Koldobsky

With any convex function F on a finite-dimensional linear space X such that F goes to infinity at infinity, we associate a Borel measure on the dual space X*. This measure is obtained by pushing forward the measure exp(-F(x))dx under the…

Functional Analysis · Mathematics 2013-04-03 Dario Cordero-Erausquin , Bo'az Klartag

Methods for measuring convexity defects of compacts in R^n abound. However, none of the those measures seems to take into account continuity. Continuity in convexity measure is essential for optimization, stability analysis, global…

Geometric Topology · Mathematics 2024-12-24 Abel Douzal , Ferdinand Jacobé de Naurois

We prove several estimates for the moments of arbitrary measures on convex bodies. We apply these estimates to show a new slicing inequality for measures on convex bodies. We also deduce estimates for the outer volume ratio distance from an…

Metric Geometry · Mathematics 2017-12-19 Sergey Bobkov , Bo'az Klartag , Alexander Koldobsky

For a permutationally invariant unconditional convex body K in R^n we define a finite sequence (K_j), j = 1, ..., n of projections of the body K to the space spanned by first j vectors of the standard basis of R^n. We prove that the…

Functional Analysis · Mathematics 2013-03-04 Piotr Nayar , Tomasz Tkocz

We generalize classical kinematic formulas for convex bodies in a real vector space $V$ to the setting of non-compact Lie groups admitting a Cartan decomposition. Specifically, let $G$ be a closed linear group with Cartan decomposition $G…

Metric Geometry · Mathematics 2025-04-10 Sílvia Anjos , Francisco Nascimento

We prove that for $s<0$, $s$-concave measures on ${\mathbb R}^n$ satisfy a thin shell concentration similar to the log-concave one. It leads to a Berry-Esseen type estimate for their one dimensional marginal distributions. We also establish…

Functional Analysis · Mathematics 2014-10-03 Matthieu Fradelizi , Olivier Guédon , Alain Pajor

Shape constraints yield flexible middle grounds between fully nonparametric and fully parametric approaches to modeling distributions of data. The specific assumption of log-concavity is motivated by applications across economics, survival…

Methodology · Statistics 2024-04-16 Robin Dunn , Aditya Gangrade , Larry Wasserman , Aaditya Ramdas

We show the existence of Lebesgue-equivalent conservative and ergodic $\sigma$-finite invariant measures for a wide class of one-dimensional random maps consisting of piecewise convex maps. We also estimate the size of invariant measures…

Dynamical Systems · Mathematics 2023-03-21 Tomoki Inoue , Hisayoshi Toyokawa

We study the log-concave measures, their characterization via the Pr\'ekopa-Leindler property and also define a subset of it whose elements are called super log-concave measures which have the property of satisfying a logarithmic Sobolev…

Probability · Mathematics 2010-05-28 Denis Feyel , A. Suleyman Ustunel

In this paper we develop tools for studying limit theorems by means of convexity. We establish bounds for the discrepancy in total variation between probability measures $\mu$ and $\nu$ such that $\nu$ is log-concave with respect to $\mu$.…

Probability · Mathematics 2022-10-24 Arturo Jaramillo , James Melbourne

In this paper we prove a series of Rogers-Shephard type inequalities for convex bodies when dealing with measures on the Euclidean space with either radially decreasing densities, or quasi-concave densities attaining their maximum at the…

Gauges, or convex distance functions are, roughly speaking, norms without symmetry. In this paper we intend to quantify how asymmetric a planar gauge can be. We introduce asymmetry measures for smooth gauges and for strictly convex gauges,…

Metric Geometry · Mathematics 2019-01-25 Vitor Balestro , Horst Martini , Ralph Teixeira

This is a significantly improved version with new applications. We show that there are many cohomogeneity one manifolds which do not admit an analytic invariant metric with non-negative sectional curvature, although they do have a smooth…

Differential Geometry · Mathematics 2014-08-06 Luigi Verdiani , Wolfgang Ziller

In $\mathbb{R}^d$, a closed, convex set has zero Lebesgue measure if and only its interior is empty. More generally, in separable, reflexive Banach spaces, closed and convex sets are Haar null if and only if their interior is empty. We…

Functional Analysis · Mathematics 2024-11-22 Davide Ravasini

In this paper the theory of uniformly convex metric spaces is developed. These spaces exhibit a generalized convexity of the metric from a fixed point. Using a (nearly) uniform convexity property a simple proof of reflexivity is presented…

Metric Geometry · Mathematics 2016-04-08 Martin Kell

We study a version of the Busemann-Petty problem for $\log$-concave measures with an additional assumption on the dilates of convex, symmetric bodies. One of our main tools is an analog of the classical large deviation principle applied to…

Probability · Mathematics 2025-02-19 Malak Lafi , Artem Zvavitch