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Original scientific paper

https://doi.org/10.3336/gm.56.1.11

Amiable and almost amiable fixed sets. Extension of the brouwer fixed point theorem

James F. Peters ; Department of Mathematics, Faculty of Arts and Sciences, Adıyaman University, 02040 Adıyaman, Turkey


Full text: english pdf 219 Kb

page 175-194

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Abstract

This paper introduces shape boundary regions in descriptive proximity forms of CW (Closure-finite Weak) spaces as a source of amiable fixed subsets as well as almost amiable fixed subsets of descriptive proximally continuous (dpc) maps. A dpc map is an extension of an Efremovič-Smirnov proximally continuous (pc) map introduced during the early-1950s by V.A. Efremovič and Yu.M. Smirnov. Amiable fixed sets and the Betti numbers of their free Abelian group representations are derived from dpc's relative to the description of the boundary region of the sets. Almost amiable fixed sets are derived from dpc's by relaxing the matching description requirement for the descriptive closeness of the sets. This relaxed form of amiable fixed sets works well for applications in which closeness of fixed sets is approximate rather than exact. A number of examples of amiable fixed sets are given in terms of wide ribbons. A bi-product of this work is a variation of the Jordan curve theorem and a fixed cell complex theorem, which is an extension of the Brouwer fixed point theorem.

Keywords

Amiable, boundary region, CW space, descriptive fixed set, descriptive proximally continuous map, descriptive proximity, wide ribbon

Hrčak ID:

259307

URI

https://hrcak.srce.hr/259307

Publication date:

24.6.2021.

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