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Related papers: About extension of upper semicontinuous multi-valu…

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We show, in particular, that a multivalued map $f$ from a closed subspace $X$ of $\mathbb R^n$ to ${\rm exp}_k(\mathbb R^n)$ has a point of period exactly $M$ if and only if its continuous extension $\tilde f: \beta X\to {\rm exp}_k(\beta…

General Topology · Mathematics 2012-02-09 R. Z. Buzyakova , A. Chigogidze

For a map $T \colon [0,1] \to [0,1]$ with an invariant measure $\mu$, we study, for a $\mu$-typical $x$, the set of points $y$ such that the inequality $|T^n x - y| < r_n$ is satisfied for infinitely many $n$. We give a formula for the…

Dynamical Systems · Mathematics 2015-05-27 Tomas Persson , Michał Rams

Some known fixed point theorems for nonexpansive mappings in metric spaces are extended here to the case of primitive uniform spaces. The reasoning presented in the proofs seems to be a natural way to obtain other general results.

General Topology · Mathematics 2021-04-09 Lech Pasicki

The paper discusses the conditions for the existence of fixed points of multivalued mappings that are not based on the linear structure of the set. The descriptions for the sets of fixed points for mappings with closed graph in compact…

General Topology · Mathematics 2016-02-23 Dmitrii Serkov

We examine conditions on a (compact metrizable) space $X$ such that for any space $Y$ and closed subspace $Z$, the set of continuous functions from $Z$ to $X$ which extend to $Y$ is either open or closed in the set of continuous functions…

General Topology · Mathematics 2012-07-31 Bruce Blackadar

We prove that a harmonic quasiconformal mapping defined on a finitely connected domain in the plane, all of whose boundary components are either points or quasicircles, admits a quasiconformal extension to the whole plane if its Schwarzian…

Complex Variables · Mathematics 2021-02-05 Iason Efraimidis

The Brouwer fixed point theorem says that any continuous function from disc to itself has a fixed point. By using simple geometrical technique we have generalized the result in manifold and proved that any continuous function on the…

Differential Geometry · Mathematics 2020-08-04 Absos Ali Shaikh , Chandan Kumar Mondal

Some fixed point results of classical theory, such as Banach's Fixed Point Theorem, have been previously extended by other authors to asymmetric spaces in recent years. The aim of this paper is to extend to asymmetric spaces some others…

General Topology · Mathematics 2023-05-17 L. Benítez-Babilonia , R. Felipe , L. Rubio

We consider semidifferentiable (possibly nonsmooth) maps, acting on a subset of a Banach space, that are nonexpansive either in the norm of the space or in the Hilbert's or Thompson's metric inherited from a convex cone. We show that the…

Functional Analysis · Mathematics 2014-03-12 Marianne Akian , Stephane Gaubert , Roger Nussbaum

Extensions of one-parameter operator semigroups on Archimedean vector lattices to their order/ru-completions are studied. Existence and uniqueness of the extension to the ru-completion is established in the class of positive semigroups. An…

Functional Analysis · Mathematics 2024-12-24 Eduard Emelyanov

We define extension maps as maps that extend a system (through adding ancillary systems) without changing the state in the original system. We show, using extension maps, why a completely positive operation on an initially entangled system…

Quantum Physics · Physics 2007-05-23 Aik-meng Kuah , E. C. G. Sudarshan

The problem involving the extension of functions from a certain class and defined on subdomains of the ambient space to the whole space is an old and a well investigated theme in analysis. A related question whether the extensions that…

Functional Analysis · Mathematics 2020-01-28 M. A. Sofi

The following two assertions are equivalent for an o-minimal expansion of an ordered group $\mathcal M=(M,<,+,0,\ldots)$. There exists a definable bijection between a bounded interval and an unbounded interval. Any definable continuous…

Logic · Mathematics 2023-05-17 Masato Fujita

We consider a global, nonlinear version of the Whitney extension problem for manifold-valued smooth functions on closed domains $C$, with non-smooth boundary, in possibly non-compact manifolds. Assuming $C$ is a submanifold with corners, or…

Differential Geometry · Mathematics 2022-09-13 David Michael Roberts , Alexander Schmeding

We investigate the invariant metrics and complex geodesics in the universal Teichm\"{u}ller space and Teichm\"{u}ller space of the punctured disk using Milin's coefficient inequalities. This technique allows us to establish that all…

Complex Variables · Mathematics 2014-05-20 Samuel L. Krushkal

We prove that strong finite total curvature complete hypersurfaces of (n+1)-euclidean space are proper and diffeomorphic to a compact manifold minus finitely many points. With an additional condition, we also prove that the Gauss map of…

Differential Geometry · Mathematics 2015-12-16 Manfredo do Carmo , Maria Fernanda Elbert

Let S be a dense sub-semigroup of the positive real numbers, and let X be a separable, reflexive Banach space. This note contains a proof that every weakly continuous contractive semigroup of operators on X over S can be extended to a…

Functional Analysis · Mathematics 2009-03-21 Eliahu Levy , Orr Shalit

We revisit Haagerup's enigmatic reduction theorem \cite[Theorems 2.1 \& 3.1]{HJX} showing how that theorem may be extended to general von Neumann algebras $\M$ equipped with an arbitrary faithful normal semifinite weight in a manner which…

Operator Algebras · Mathematics 2025-06-10 Louis Labuschagne , Quanhua Xu

We adapt the definition of the Vietoris map to the framework of finite topological spaces and we prove some coincidence theorems. From them, we deduce a Lefschetz fixed point theorem for multivalued maps that improves recent results in the…

Dynamical Systems · Mathematics 2020-10-27 Pedro J. Chocano , Manuel A. Morón , Francisco R. Ruiz del Portal

Let $X$ and $Y$ be the Hausdorff topological spaces and let $A$ be both an $\fs$- and $\gd$- subset of $X$. Let also $f\cn A\to Y$ be a function for which the inverse image of every open subset $U\subset Y$ is $\fs$ in $X$. We show that $f$…

General Topology · Mathematics 2023-12-08 Waldemar Sieg