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Light maps and extensional dimension

โœ Scribed by A.N. Dranishnikov; V.V. Uspenskij


Book ID
104295175
Publisher
Elsevier Science
Year
1997
Tongue
English
Weight
640 KB
Volume
80
Category
Article
ISSN
0166-8641

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โœฆ Synopsis


We show that any light map f : X + Y between compact spaces admits a decomposition f = gh, where g : 2 + Y is a finite-to-one map of a special type and h : X + 2 has arbitrarily small fibers. It follows that light maps between compact spaces do not lower extensional dimension. Our theorem yields a positive answer to Problem 423 from "Open Problems in Topology". We also generalize Hurewicz' theorem on dimension-raising maps to the case of extensional dimension.


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