TFT
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For n\geq 2, is there a smooth map f: S^n\rightarrow E (E is the equator of S^n) which has the property that the restriction of f to E is a diffeomorphism from E to E?
The discussion addresses the existence of a smooth map f: S^n → E, where E is the equator of S^n, for n ≥ 2. It concludes that such a function cannot exist, as demonstrated through homology theory and the properties of diffeomorphisms. The argument hinges on the contradiction arising from the degree of the restriction of the map, leading to an absurdity in the homological diagram. This establishes that there is no retraction from the n-disk to its boundary in this context.
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