| Title: | Some cohomological aspects of the Banach fixed point principle (English) | 
| Author: | Janoš, Ludvík | 
| Language: | English | 
| Journal: | Mathematica Bohemica | 
| ISSN: | 0862-7959 (print) | 
| ISSN: | 2464-7136 (online) | 
| Volume: | 136 | 
| Issue: | 3 | 
| Year: | 2011 | 
| Pages: | 333-336 | 
| Summary lang: | English | 
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| Category: | math | 
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| Summary: | Let $T\colon  X\to X$ be a continuous selfmap of a compact metrizable space $X$. We prove the equivalence of the following two statements: (1) The mapping $T$ is a Banach contraction relative to some compatible metric on $X$. (2) There is a countable point separating family $\mathcal {F}\subset \mathcal {C}(X)$ of non-negative functions $f\in \mathcal {C}(X)$ such that for every $f\in \mathcal {F}$ there is $g\in \mathcal {C}(X)$ with $f=g-g\circ T$. (English) | 
| Keyword: | Banach contraction | 
| Keyword: | cohomology | 
| Keyword: | cocycle | 
| Keyword: | coboundary | 
| Keyword: | separating family | 
| Keyword: | core | 
| MSC: | 54H20 | 
| MSC: | 54H25 | 
| idZBL: | Zbl 1249.54081 | 
| idMR: | MR2893980 | 
| DOI: | 10.21136/MB.2011.141653 | 
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| Date available: | 2011-09-22T15:02:51Z | 
| Last updated: | 2020-07-29 | 
| Stable URL: | http://hdl.handle.net/10338.dmlcz/141653 | 
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| Reference: | [1] Bakakhanian, A.: Cohomological Methods in Group Theory.Marcel Dekker, New York (1972). | 
| Reference: | [2] Janoš, L.: The Banach contraction mapping principle and cohomology.Comment. Math. Univ. Carolin. 41 (2000), 605-610. MR 1795089 | 
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