Semi-algebraic neighborhoods of closed semi-algebraic sets
نویسندگان
چکیده
منابع مشابه
Semi-algebraic neighborhoods of closed semi-algebraic sets
— Given a closed (not necessarly compact) semi-algebraic set X in Rn, we construct a non-negative semi-algebraic C2 function f such that X=f−1(0) and such that for δ > 0 sufficiently small, the inclusion of X in f−1([0, δ]) is a retraction. As a corollary, we obtain several formulas for the Euler characteristic of X. Résumé. — Étant donné un ensemble semi-algébrique fermé (non nécessairement co...
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ژورنال
عنوان ژورنال: Annales de l’institut Fourier
سال: 2009
ISSN: 0373-0956,1777-5310
DOI: 10.5802/aif.2435