Rings of continuous functions and the branch set of a covering

Mulero, M.

doi:10.1090/S0002-9939-98-04353-6

Rings of continuous functions and the branch set of a covering
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Proc. Amer. Math. Soc. 126 (1998), 2183-2189 Request permission

Abstract:

This paper gives a characterization of the branch set of a finite covering $X\to S$ of a topological space $S$, by means of finite $C(S)$-subalgebras $A$ of $C(X)$ that separate points in $X$ and the module $\Omega _{A/C(S)}$ of its Kähler differentials.

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