Pseudo-elliptic bundles, deformation data, and the reduction of Galois covers
We study a class of filtered flat vector bundles of rank 2 which we call pseudo-eeliptic bundles. We construct pseudo-elliptic bundles starting from a deformation datum defined over the function field of a curve over an algebraically closed field of positive characteristic. This leads us to study a variant of Dwork's accessary parameter problem. We give applications of our results to Galois theory.