Wednesday, 15 July 2015

real analysis - Uniformly continuous bijection from X to the Cantor set




Let X be a metric space, and C be the Cantor set (equipped with the standard topology).




Let f:XC be a uniformly continuous function. Assume that f is
a bijection. Does it follow that f is a homeomorphism?




I know that if X is compact, then the answer is yes. This follows from the following theorem:





A continuous bijection from a compact set to a Hausdorff space is
homeomorphism.




I am hoping that the condition "uniform continuity" is strong enough to cover the case even when K is not compact.



I appreciate any help :)


Answer



Let ρ be the discrete metric on the Cantor set C, and let d be the usual metric; then the identity map from C,ρ to C,d is a uniformly continuous bijection but not a homeomorphism.


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