ALGEBRAIC AND NORI FUNDAMENTAL GERBES

Abstract

In this paper we extend the generalized algebraic fundamental group constructed in Esnault and Hogadi, (Trans. Amer. Math. Soc.364(5) (2012), 2429–2442) to general fibered categories using the language of gerbes. As an application we obtain a Tannakian interpretation for the Nori fundamental gerbe defined in Borne and Vistoli (J. Algebraic Geom.(2014), S1056–3911, 00638-X) for nonsmooth non-pseudo-proper algebraic stacks.