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We study the generic behavior of the method of successive approximations for set-valued mappings in separable Banach spaces. We consider the case of nonexpansive mappings with convex and compact point images and show that for the typical…

泛函分析 · 数学 2023-01-27 Christian Bargetz , Emir Medjic , Katriin Pirk

Any solid object can be decomposed into a collection of convex polytopes (in short, convexes). When a small number of convexes are used, such a decomposition can be thought of as a piece-wise approximation of the geometry. This…

计算机视觉与模式识别 · 计算机科学 2020-04-14 Boyang Deng , Kyle Genova , Soroosh Yazdani , Sofien Bouaziz , Geoffrey Hinton , Andrea Tagliasacchi

The convex body isoperimetric conjecture in the plane asserts that the least perimeter to enclose given area inside a unit disk is greater than inside any other convex set of area $\pi$. In this note we confirm two cases of the conjecture:…

微分几何 · 数学 2021-04-13 Bo-Hshiung Wang , Ye-Kai Wang

In the spirit of the Genetics of the Regular Figures, by L. Fejes T\'oth, we prove the following theorem: If $2n$ points are selected in the $n$-dimensional Euclidean ball $B^n$ so that the smallest distance between any two of them is as…

度量几何 · 数学 2007-05-23 Wlodzimierz Kuperberg

The (combinatorial) diameter of a polytope $P \subseteq \mathbb R^d$ is the maximum value of a shortest path between a pair of vertices on the 1-skeleton of $P$, that is the graph where the nodes are given by the $0$-dimensional faces of…

组合数学 · 数学 2018-07-24 Laura Sanità

In this article we prove a global result in the spirit of Basener's theorem regarding the relation between q-pseudoconvexity and q-holomorphic convexity: we prove that any smoothly bounded strictly q-pseudoconvex open subset of the complex…

复变函数 · 数学 2018-09-05 George-Ionut Ionita , Ovidiu Preda

We study a property of $2$-strong uniqueness of a best approximation in a class of finite-dimensional complex normed spaces, for which the unit ball is an absolutely convex hull of finite number of points and in its dual class. We prove…

泛函分析 · 数学 2025-06-02 Tomasz Kobos , Grzegorz Lewicki

Given two arbitrary closed sets in Euclidean space, a simple transversality condition guarantees that the method of alternating projections converges locally, at linear rate, to a point in the intersection. Exact projection onto nonconvex…

最优化与控制 · 数学 2018-11-06 Dmitriy Drusvyatskiy , Adrian S. Lewis

We prove the theorem mentioned in the title, for ${\mathbb{R}}^n$, where $n \ge 3$. The case of the simplex was known previously. Also, the case $n=2$ was settled, but there the infimum was some well-defined function of the side lengths. We…

微分几何 · 数学 2017-07-28 N. V. Abrosimov , E. Makai, , A. D. Mednykh , Yu. G. Nikonorov , G. Rote

In this note, we derive an asymptotically sharp upper bound on the number of lattice points in terms of the volume of centrally symmetric convex bodies. Our main tool is a generalization of a result of Davenport that bounds the number of…

度量几何 · 数学 2013-10-25 Matthias Henze

We study geometric properties of coordinate projections. Among other results, we show that if a body K in R^n has an "almost extremal" volume ratio, then it has a projection of proportional dimension which is close to the cube. We compare…

泛函分析 · 数学 2016-12-23 S. Mendelson , R. Vershynin

We study the approximability of general convex sets in $\mathbb{R}^n$ by intersections of halfspaces, where the approximation quality is measured with respect to the standard Gaussian distribution $N(0,I_n)$ and the complexity of an…

计算复杂性 · 计算机科学 2023-11-16 Anindya De , Shivam Nadimpalli , Rocco A. Servedio

We revisit two NP-hard geometric partitioning problems - convex decomposition and surface approximation. Building on recent developments in geometric separators, we present quasi-polynomial time algorithms for these problems with improved…

计算几何 · 计算机科学 2014-04-16 Sayan Bandyapadhyay , Santanu Bhowmick , Kasturi Varadarajan

The Euclidean projection onto a convex set is an important problem that arises in numerous constrained optimization tasks. Unfortunately, in many cases, computing projections is computationally demanding. In this work, we focus on…

最优化与控制 · 数学 2021-09-22 Ilnura Usmanova , Maryam Kamgarpour , Andreas Krause , Kfir Yehuda Levy

We consider a generalization of the hyperplane problem to arbitrary measures in place of volume and to sections of lower dimensions. We prove this generalization for unconditional convex bodies and for duals of bodies with bounded volume…

度量几何 · 数学 2015-03-24 Alexander Koldobsky

A suitable measure for the similarity of shapes represented by parameterized curves or surfaces is the Fr\'echet distance. Whereas efficient algorithms are known for computing the Fr\'echet distance of polygonal curves, the same problem for…

计算几何 · 计算机科学 2007-05-23 Helmut Alt , Maike Buchin

In the Onsager model of one-component hard-particle systems, the entire phase behaviour is dictated by a function of relative orientation, which represents the amount of space excluded to one particle by another at this relative…

软凝聚态物质 · 物理学 2019-02-20 Jamie M. Taylor

Using an optimal containment approach, we quantify the asymmetry of convex bodies in $\mathbb{R}^n$ with respect to reflections across affine subspaces of a given dimension. We prove general inequalities relating these ''Minkowski…

In this work, we consider a class of convex optimization problems in a real Hilbert space that can be solved by performing a single projection, i.e., by projecting an infeasible point onto the feasible set. Our results improve those…

最优化与控制 · 数学 2024-04-10 Hoa T. Bui , Regina S. Burachik , Evgeni A. Nurminski , Matthew K. Tam

If we fix the angles at the vertices of a convex planar $n$-gon, the lengths of its edges must satisfy two linear constraints in order for it to close up. If we also require unit perimeter, our vectors of $n$ edge lengths form a convex…

度量几何 · 数学 2020-02-20 Lyle Ramshaw , James B. Saxe