English
Related papers

Related papers: Centre of a compact convex set

200 papers

The main result states that every convex set-valued function defined on a real interval with compact values in a locally convex space, admits an affine selection. In the case if the target space is a real line and the values are closed real…

Functional Analysis · Mathematics 2008-07-28 Szymon Wasowicz

We characterize inclusions of compact noncommutative convex sets with the property that every continuous affine function on the smaller set can be extended to a continuous affine function on the larger set with a uniform bound. As an…

Operator Algebras · Mathematics 2025-08-06 Adam Humeniuk , Matthew Kennedy , Nicholas Manor

This paper extends the Kadison duality between compact convex sets and function systems to the setting of partial convexity. A partially convex set is a set that is convex in a designated set of convex variables when the others are held…

Functional Analysis · Mathematics 2026-05-06 Tea Štrekelj

Let $C$ be a convex subset of a locally convex space. We provide optimal approximate fixed point results for sequentially continuous maps $f\colon C\to\bar{C}$. First we prove that if $f(C)$ is totally bounded, then it has an approximate…

Functional Analysis · Mathematics 2013-02-27 Cleon S. Barroso , Ondřej F. K. Kalenda , Michel P. Rebouças

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

This work is devoted to a systematic study of symplectic convexity for integrable Hamiltonian systems with elliptic and focus-focus singularities. A distinctive feature of these systems is that their base spaces are still smooth manifolds…

Symplectic Geometry · Mathematics 2018-09-18 Tudor Ratiu , Christophe Wacheux , Nguyen Tien Zung

Let X be a compact convex set and let ext X stand for the set of extreme points of X. We show that an affine function with the point of continuity property on X satisfies the minimum principle. As a corollary we obtain a generalization of a…

Functional Analysis · Mathematics 2018-01-25 Petr Dostál , Jiří Spurný

The class of $\mu$-compact sets can be considered as a natural extension of the class of compact metrizable subsets of locally convex spaces, to which the particular results well known for compact sets can be generalized. This class…

Functional Analysis · Mathematics 2010-04-23 M. E. Shirokov

We prove conditions for the existence of a continuous linear right inverse for a surjective convolution operator in spaces of germs of analytic functions on convex subsets of the complex plane. Considered convex sets have a countable…

Functional Analysis · Mathematics 2018-10-22 S. N. Melikhov , L. V. Khanina

We generalize the theory of base norm spaces to the complex case, and further to the noncommutative setting relevant to `quantum convexity'. In particular, we establish the duality between complex Archimedean order unit spaces and complex…

Operator Algebras · Mathematics 2026-02-16 David P. Blecher , Damon M. Hay

In this paper we first extend from normed spaces to locally convex spaces some characterizations of denting points in convex sets. On the other hand, we also prove that in an infrabarreled locally convex space a point in a convex set is…

Functional Analysis · Mathematics 2024-01-17 Fernando García-Castaño , M. A. Melguizo Padial , G. Parzanese

This note deals with certain properties of convex functions. We provide results on the convexity of the set of minima of these functions, the behaviour of their subgradient set under restriction, and optimization of these functions over an…

Optimization and Control · Mathematics 2017-03-21 Miel Sharf , Daniel Zelazo

In this paper we establish a general framework in which the verification of support theorems for generalized convex functions acting between an algebraic structure and an ordered algebraic structure is still possible. As for the domain…

Functional Analysis · Mathematics 2020-12-07 Andrzej Olbryś , Zsolt Páles

Convex geometry has recently attracted great attention as a framework to formulate general probabilistic theories. In this framework, convex sets and affine maps represent the state spaces of physical systems and the possible dynamics,…

Geometric Topology · Mathematics 2015-06-10 Gen Kimura , Koji Nuida

We introduce notions of concavity for functions on balanced polyhedral spaces, and we show that concave functions on such spaces satisfy several strong continuity properties.

Combinatorics · Mathematics 2021-09-14 Ana María Botero , José Ignacio Burgos Gil , Martín Sombra

A method of proving local continuity of concave functions on convex set possessing the $\mu$-compactness property is presented. This method is based on a special approximation of these functions. The class of $\mu$-compact sets can be…

Functional Analysis · Mathematics 2010-06-22 M. E. Shirokov

We endow the set of complements of a fixed subspace of a projective space with the structure of an affine space, and show that certain lines of such an affine space are affine reguli or cones over affine reguli. Moreover, we apply our…

Algebraic Geometry · Mathematics 2024-02-13 Andrea Blunck , Hans Havlicek

An affine version of the linear subspace concentration inequality as proposed by Wu is established for centered convex bodies. This generalizes results from Wu and Freyer, Henk, Kipp on polytopes to convex bodies.

Metric Geometry · Mathematics 2024-09-24 Katharina Eller , Ansgar Freyer

We describe all metric spaces that have sufficently many affine functions. As an application we obtain a metric characterization of linear-convex subsets of Banach spaces.

Metric Geometry · Mathematics 2013-04-25 Petra Schwer , Alexander Lytchak

We prove that two dimensional convex subsets of spherical buildings are either buildings or have a center.

Metric Geometry · Mathematics 2007-05-23 Andreas Balser , Alexander Lytchak
‹ Prev 1 2 3 10 Next ›