English

Triangulation et cohomologie \'{e}tale sur une courbe analytique

Algebraic Geometry 2007-05-23 v1

Abstract

Let kk be a non-archimedean complete valued field and let X be a smooth Berkovich analytic kk-curve. Let FF be a finite locally constant \'{e}tale sheaf on kk whose torsion is prime to the residue characteristic. We denote by X|X| the underlying topological space and by π\pi the canonical map from the \'{e}tale site to X|X|. In this text we define a triangulation of XX, we show that it always exists and use it to compute H0(X,Rqπ_F)H^{0}(|X|,R^{q}\pi\_{*}F) and H1(X,Rqπ_F)H^{1}(|X|,R^{q}\pi\_{*}F). If XX is the analytification of an algebraic curve we give sufficient conditions so that those groups are isomorphic to their algebraic counterparts ; if the cohomology of kk has a dualizing sheaf in some degree dd (e.g kk is pp-adic, or k=C((t))k=C((t))) then we prove a duality theorem between H0(X,Rqπ_F)H^{0}(|X|,R^{q}\pi\_{*}F) and H1_c(X,Rd+1π_G)H^{1}\_ {c}(|X|,R^{d+1}\pi\_{*}G) where GG is the tensor product of the dual sheaf of FF with the dualizing sheaf and the sheaf of nn-th roots of unity.

Keywords

Cite

@article{arxiv.math/0501508,
  title  = {Triangulation et cohomologie \'{e}tale sur une courbe analytique},
  author = {Antoine Ducros},
  journal= {arXiv preprint arXiv:math/0501508},
  year   = {2007}
}
R2 v1 2026-07-22T17:15:00.599Z