Computation of the Similarity Class of the p-Curvature
arXiv:1605.06126 · doi:10.1145/2930889.2930897
Abstract
The -curvature of a system of linear differential equations in positive characteristic is a matrix that measures how far the system is from having a basis of polynomial solutions. We show that the similarity class of the -curvature can be determined without computing the -curvature itself. More precisely, we design an algorithm that computes the invariant factors of the -curvature in time quasi-linear in . This is much less than the size of the -curvature, which is generally linear in . The new algorithm allows to answer a question originating from the study of the Ising model in statistical physics.
Proceedings of ISSAC 2016, to appear