Let (X,T) be a Hausdorff space and K = {A ⊂ X| A∩K is open ∀K ⊂ X compact}. Show that K is a finer topology than K, and that (X,K) is compact.
The topology is finer because, if is open then, by definition it is open in subspace topology, infact open for evry compact subset of i.e. is open in Hence Hence has a finer topology. But its not compact if is not.
Counterexample : Take the real line and endow it with the the standard topology. Then it is Hausdorff, but real line is non-compact. In particular take, . This is a cover in since it has finer topology. But it has no finite cover. Infact take finitely many and consider the largest Then remains uncovered in that collection.
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