English

Points fixes des applications compactes dans les espaces ULC

General Topology 2010-10-13 v1 Algebraic Topology Functional Analysis

Abstract

A topological space is locally equiconnected if there exists a neighborhood UU of the diagonal in X×XX\times X and a continuous map λ:U×[0,1]X\lambda:U\times[0,1]\to X such that λ(x,y,0)=x\lambda(x,y,0)=x, λ(x,y,1)=y\lambda(x,y,1)=y et λ(x,x,t)=x\lambda(x,x,t)=x for (x,y)U(x,y)\in U and (x,t)X×[0,1](x,t)\in X\times[0,1]. This class contains all ANRs, all locally contractible topological groups and the open subsets of convex subsets of linear topological spaces. In a series of papers, we extended the fixed point theory of compact continuous maps, which was well developped for ANRs, to all separeted locally equiconnected spaces. This generalization includes a proof of Schauder's conjecture for compact maps of convex sets. This paper is a survey of that work. The generalization has two steps: the metrizable case, and the passage from the metrizable case to the general case. The metrizable case is, by far, the most difficult. To treat this case, we introduced in [4] the notion of algebraic ANR. Since the proof that metrizable locally equiconnected spaces are algebraic ANRs is rather difficult, we give here a detaled sketch of it in the case of a compact convex subset of a metrizable t.v.s.. The passage from the metrizable case to the general case uses a free functor and representations of compact spaces as inverse limits of some special inverse systems of metrizable compacta.

Keywords

Cite

@article{arxiv.1010.2401,
  title  = {Points fixes des applications compactes dans les espaces ULC},
  author = {Robert Cauty},
  journal= {arXiv preprint arXiv:1010.2401},
  year   = {2010}
}
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