On the S-fundamental group scheme

On the Local Unipotent Fundamental Group Scheme

We prove a local, unipotent, analog of Kedlaya’s theorem for the pro-p part of the fundamental group of integral affine schemes in characteristic p.

The Fundamental Group of S-manifolds

We address the problem of computing the fundamental group of a symplectic S1-manifold for non-Hamiltonian actions on compact manifolds, and for Hamiltonian actions on non-compact manifolds with a proper moment map. We generalize known results for compact manifolds equipped with a Hamiltonian S1-action. Several examples are presented to illustrate our main results.

The Fundamental Group for the Complement of Cayley ’ s Singularities ∗

Given a singular surface X, one can extract information on it by investigating the fundamental group π1(X − SingX). However, calculation of this group is non-trivial, but it can be simplified if a certain invariant of the branch curve of X – called the braid monodromy factorization – is known. This paper shows, taking the Cayley cubic as an example, how this fundamental group can be computed by...

2 5 M ay 2 00 6 Some Remarks on the Local Fundamental Group Scheme

2 6 M ay 2 00 6 Some Remarks on the Local Fundamental Group Scheme