A Short Proof that Some Mappings of the Unit Ball of ℓ2 Are Never Nonexpansive

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RESEARCH PRODUCT

A Short Proof that Some Mappings of the Unit Ball of ℓ2 Are Never Nonexpansive

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Unit sphere Combinatorics General Mathematics 010102 general mathematics 0101 mathematics Fixed point 01 natural sciences Mathematics

description

It is known that some particular self-mappings of the closed unit ball Bl2 of l2 with no fixed points cannot be nonexpansive with respect to any renorming of l2. We give here a short proof of this ...

year	journal	country	edition	language
2020-03-30	The American Mathematical Monthly

https://doi.org/10.1080/00029890.2020.1704168

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