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arXiv · 1009.0363

Equivariant Euler characteristics and sheaf resolvents

Ph. Cassou-Nogu`es·M. J. Taylor
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Abstract

For certain tame abelian covers of arithmetic surfaces X/Y we obtain striking formulas, involving a quadratic form derived from intersection numbers, for the equivariant Euler characteristics of both the canonical sheaf !X/Y and also its square root !1/2 X/Y . These formulas allow us us to carry out explicit calculations; in particular, we are able to exhibit examples where these two Euler characteristics and that of the the structure sheaf of X are all different and non-trivial. Our results are obtained by using resolvent techniques together with the local Riemann-Roch approach developed in [CPT].

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Ph. Cassou-Nogu`es, M. J. Taylor. 2010-09-02. Equivariant Euler characteristics and sheaf resolvents. https://arxiv.org/abs/1009.0363

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