Let X and Y be reduced complex spaces with countable topology. Let π : X → Y be a locally semi-finite holomorphic map such that the analytic set π −1 (S(Y )) is nowhere dense in X. If Y is complete Kähler, then we prove that X is also complete Kähler. Especially if π : X → Y is a (not necessarily finitely sheeted) ramified covering over a complete Kähler space Y , then X is also complete Kähler.
Introduction.In the category of the complex spaces there are some theorems of the following form. Let X and Y be complex spaces and π : X → Y a holomorphic map with a property (A). If Y satisfies a property (B), then X also satisfies the same property (B).If π is finite and Y is Stein, then X is also Stein (see Proposition 52.18 of Kaup-Kaup [4, p. 236]). If π : X → Y is an unramified covering over a Stein space Y , then X is also Stein by Satz 2.1 of Stein [7]. These results are generalized by Le Barz [5]. Namely if π is locally semi-finite and Y is Stein, then X is also Stein. On the other hand Vâjâitu [8] proved that if π is a holomorphic map with discrete fibers and Y is Kähler, then X is also Kähler.We consider the case of the local semi-finiteness as the property (A) and the complete Kählerity as the property (B). Throughout this paper all complex spaces are supposed to be reduced and with countable topology. We denote by S(Y ) the singular locus of a complex space Y . Our result is the following theorem.
Let R be a unital *-ring and let a, b,w ? R. In this paper, we give some new
characterizations on w-core inverses in R. In particular, it is shown that a
is w-core invertible if and only if it is w(aw)n?1- core invertible for any
positive integer n, in which case, the representations of the w-core inverse
and the w(aw)n?1-core inverse of a are both presented. We further
characterize w-core inverses by Hermitian elements (or projections) and
units.
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