MathSciDoc: An Archive for Mathematician ∫

Let $X$ be a smooth connected algebraic curve over an algebraically closed field, let $S$ be a finite closed subset in $X$, and let $\mathcal F_0$ be a lisse $\ell$-torsion sheaf on $X-S$. We study the deformation of $\mathcal F_0$. The universal deformation space is a formal scheme. Its generic fiber has a rigid analytic space structure. By studying this rigid analytic space, we prove a conjecture of Katz which says that if a lisse $\overline{\mathbb Q}_\ell$-sheaf $\mathcal F$ is irreducible and physically rigid, then it is cohomologically rigid, under the extra condition that $\mathcal F\mod \ell$ is absolutely irreducible or that $\mathcal F$ has finite monodromy.

deformation of Galois representations, formal scheme, rigid analytic space