English
Related papers

Related papers: Weakly Externally Hyperconvex Subsets and Hypercon…

200 papers

We give a proof to the following theorem, which is well-known among experts: A connected subcomplex $W$ of a finite dimensional CAT(0) cubed complex $X$ is convex if and only if Lk$(v, W)$ is a full subcomplex of Lk$(v, X)$ for every vertex…

Geometric Topology · Mathematics 2023-03-21 Shunsuke Sakai , Makoto Sakuma

We show that in complete metric spaces, $4$-hyperconvexity is equivalent to finite hyperconvexity. Moreover, every complete, almost $n$-hyperconvex metric space is $n$-hyperconvex. This generalizes among others results of Lindenstrauss and…

Metric Geometry · Mathematics 2016-10-12 Benjamin Miesch , Maël Pavón

The main results of the paper: {\bf (1)} The dual Banach space $X^*$ contains a linear subspace $A\subset X^*$ such that the set $A^{(1)}$ of all limits of weak$^*$ convergent bounded nets in $A$ is a proper norm-dense subset of $X^*$ if…

Functional Analysis · Mathematics 2013-02-26 Mikhail I. Ostrovskii

We determine the homeomorphism type of the hyperspace of positively curved $C^\infty$ convex bodies in $\mathbb R^n$, and derive various properties of its quotient by the group of Euclidean isometries. We make a systematic study of…

General Topology · Mathematics 2017-06-08 Igor Belegradek

We classify the Lie algebras of infinitesimal CR automorphisms of weakly pseudoconvex hypersurfaces of finite multitype in $\mathbb C^N$. In particular, we prove that such manifolds admit neither nonlinear rigid automorphisms, nor real or…

Complex Variables · Mathematics 2022-03-23 Shin-Young Kim , Martin Kolar

We investigate the regularity of the marginals onto hyperplanes for sets of finite perimeter. We prove, in particular, that if a set of finite perimeter has log-concave marginals onto a.e. hyperplane then the set is convex.

Metric Geometry · Mathematics 2015-02-24 Alessio Figalli , David Jerison

We establish how a higher local field can be described as a locally convex vector space once an embedding of a local field into it has been fixed. This extends previous results that had been obtained in the two-dimensional case. In…

Number Theory · Mathematics 2013-02-01 Alberto Camara

We consider polyhedral approximations of strictly convex compacta in finite dimensional Euclidean spaces (such compacta are also uniformly convex). We obtain the best possible estimates for errors of considered approximations in the…

Functional Analysis · Mathematics 2010-10-13 Maxim V. Balashov , Dušan Repovš

We introduce a class of combinatorial hypersurfaces in the complex projective space. They are submanifolds of codimension~2 in $\C P^n$ and are topologically "glued" out of algebraic hypersurfaces in $(\C^*)^n$. Our construction can be…

Algebraic Geometry · Mathematics 2016-09-07 Ilia Itenberg , Eugenii Shustin

Properties of two classes of generally convex sets in the n-dimentional real Euclidean space, called m-semiconvex and weakly m-semiconvex, 1<=m<n, are investigated in the present work. In particular, it is established that an open set with…

Geometric Topology · Mathematics 2017-11-15 Tetiana Osipchuk

We present an algorithm that enumerates and classifies all edge-to-edge gluings of unit squares that correspond to convex polyhedra. We show that the number of such gluings of $n$ squares is polynomial in $n$, and the algorithm runs in time…

Computational Geometry · Computer Science 2021-11-30 Stefan Langerman , Nicolas Potvin , Boris Zolotov

The present work concerns generalized convex sets in the real multi-dimensional Euclidean space, known as weakly $1$-convex and weakly $1$-semiconvex sets. An open set is called weakly $1$-convex (weakly $1$-semiconvex) if, through every…

General Topology · Mathematics 2024-12-03 Tetiana M. Osipchuk

We classify weakly Einstein submanifolds in space forms that satisfy Chen's equality. We also give a classification of weakly Einstein hypersurfaces in space forms that satisfy the semisymmetric condition. In addition, we discuss some…

Differential Geometry · Mathematics 2023-12-01 Jihun Kim , JeongHyeong Park

From descent theory to higher geometry, the idea of gluing has been embedded in many elegant and powerful techniques, proving instrumental for the solution of many problems. In this paper, we introduce a framework that allows to link…

Category Theory · Mathematics 2026-02-25 Rita Fioresi , Angelica Simonetti , Ferdinando Zanchetta

In this paper we address the reverse isoperimetric inequality for convex bodies with uniform curvature constraints in the hyperbolic plane $\mathbb{H}^2$. We prove that the\textit{ thick $\lambda$-sausage} body, that is, the convex domain…

Metric Geometry · Mathematics 2025-10-07 Maria Esteban

In the paper "Isoperimetry of waists and local versus global asymptotic convex geometries", it was proved that the existence of nicely bounded sections of two symmetric convex bodies K and L implies that the intersection of randomly rotated…

Functional Analysis · Mathematics 2016-12-23 Mark Rudelson , Roman Vershynin

We study the class of compact convex subsets of a topological vector space which admits a strictly convex and lower semicontinuous function. We prove that such a compact set is embeddable in a strictly convex dual Banach space endowed with…

Functional Analysis · Mathematics 2015-10-28 L. García-Lirola , J. Orihuela , M. Raja

We prove a sharp lower bound for the Tanaka-Webster holomorphic sectional curvature of strictly pseudoconvex real hypersurfaces that are "semi-isometrically" immersed in a K\"ahler manifold of nonnegative holomorphic sectional curvature…

Complex Variables · Mathematics 2022-10-28 Duong Ngoc Son

The notion of super weak compactness for subsets of Banach spaces is a strengthening of the weak compactness that can be described as a local version of super-reflexivity. A recent result of K. Tu which establishes that the closed convex…

Functional Analysis · Mathematics 2021-07-13 Gilles Lancien , Matias Raja

Let $\Delta=\Delta_1\times\ldots\times \Delta_d\subseteq\mathbb{R}^n$, where $\mathbb{R}^n=\mathbb{R}^{n_1}\times\cdots\times\mathbb{R}^{n_d}$ with each $\Delta_i\subseteq\mathbb{R}^{n_i}$ a non-degenerate simplex of $n_i$ points. We prove…

Combinatorics · Mathematics 2023-01-27 Neil Lyall , Akos Magyar