σ-Galois theory of linear difference equations
arXiv:1304.2649 · doi:10.1093/imrn/rnu060
Abstract
We develop a Galois theory for systems of linear difference equations with an action of an endomorphism σ. This provides a technique to test whether solutions of such systems satisfy σ-polynomial equations and, if yes, then characterize those. We also show how to apply our work to study isomonodromic difference equations and difference algebraic properties of meromorphic functions.