Computing the equivariant Euler characteristic of Zariski and étale sheaves on curves

Bernhard Köck

We prove an equivariant Grothendieck-Ogg-Shafarevich formula. This formula may be viewed as an étale analogue of well-known formulas for Zariski sheaves generalizing the classical Chevalley-Weil formula. We give a new approach to those formulas (first proved by Ellingsrud/Lønsted, Nakajima, Kani and Ksir) which can also be applied in the étale case.

Homology, Homotopy and Applications, Vol. 7 (2005), No. 3, pp.83-98.

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