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19962026
most citedOn the classification of rank two representations of quasiprojective fundamental groups

64 citations · 473 across the 56 of their papers we have counts for

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7 papers · 1 filter

alg-geom1998★ 2 cited

Secondary Kodaira-Spencer classes and nonabelian Dolbeault cohomology

Carlos Simpson

If is a smooth projective variety moving in a family, we define a secondary Kodaira-Spencer class for nonabelian Dolbeault cohomology of with coefficients…

alg-geom1997★ 16 cited

Limits in -categories

Carlos Simpson

We define notions of direct and inverse limits in an -category. We prove that the -category of fibrant -categories admits direct and inverse limits. At the end w…

alg-geom1997★ 56 cited

Mixed twistor structures

Carlos Simpson

The purpose of this paper is to introduce the notion of mixed twistor structure, a generalization of the notion of mixed Hodge structure. The utility of this notion is to make poss…

alg-geom1997★ 38 cited

A closed model structure for -categories, internal , -stacks and generalized Seifert-Van Kampen

Carlos Simpson

We define a closed model category containing the -nerves defined by Tamsamani, and admitting internal . This allows us to construct the -category by taking the…

alg-geom1996★ 43 cited

Algebraic (geometric) -stacks

Carlos Simpson

We propose a generalization of Artin's definition of algebraic stack, which we call {\em geometric -stack}. The main observation is that there is an inductive structure to the d…

alg-geom1996★ 5 cited

A relative notion of algebraic Lie group and applications to -stacks

Carlos Simpson

If is a scheme of finite type over $k=\cc $, let $\Xx /S$ denote the big etale site of schemes over . We introduce {\em presentable group sheaves}, a full subcategory of the…