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Eine Bemerkung zu einem Satz von E. Becker und D. Gondard

Jean-Louis Colliot-Th'el`ene
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Abstract

Given a smooth, projective irreducible variety over the reals, various algebraic formulas have been given for the number of real connected components of the set of real points. In this note I compare a formula of E. Becker and D. Gondard (1995) with a formula I gave in 1978. I show how one may deduce one from the other by using a purity theorem of M. Rost (1990). ----- E. Becker und D. Gondard haben eine algebraische Formel fuer die Anzahl von Zusammenhangskomponenten des Raumes der reellen Punkte einer reellen, glatten, projektiven Varietaet gebegen. In einer viel frueheren Arbeit hatte ich eine andere algebraische Formel fuer diese Anzahl gegeben. In dieser Note zeige ich, wie man direkt von einer Formel zur anderen gehen kann. Dabei wird ein Reinheitssatz von M. Rost angewandt.

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Jean-Louis Colliot-Th'el`ene. 2005-02-25. Eine Bemerkung zu einem Satz von E. Becker und D. Gondard. https://arxiv.org/abs/math/0502538

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