Invariant de Serre et fibre de Milnor analytique

In this Note, we refine the notion of motivic Serre invariants. We study the behaviour of these invariants under ramification. We establish a trace formula, which yields a cohomological interpretation of the motivic Serre invariants, in terms of the Lefschetz numbers of the monodromy action on the nearby cycles. To cite this article: J. Nicaise, J. Sebag, C. R. Acad. Sci. Paris, Ser. I 341 (2005).