Effect of increasing the ramification on pseudo-deformation rings
Abstract
Given a continuous, odd, semi-simple -dimensional representation of over a finite field of odd characteristic and a prime not dividing , we study the relation between the universal deformation rings of the corresponding pseudo-representation for the groups and . As a related problem, we investigate when the universal pseudo-representation arises from an actual representation over the universal deformation ring. Under some hypotheses, we prove analogues of theorems of Boston and B\"{o}ckle for the reduced pseudo-deformation rings. We improve these results when the pseudo-representation is unobstructed and does not divide . When the pseudo-representation is unobstructed and divides , we prove that the universal deformation rings in characteristic and of the pseudo-representation for are not local complete intersection rings. As an application of our main results, we prove a big theorem.
Keywords
Cite
@article{arxiv.1907.06608,
title = {Effect of increasing the ramification on pseudo-deformation rings},
author = {Shaunak V. Deo},
journal= {arXiv preprint arXiv:1907.06608},
year = {2021}
}
Comments
41 Pages, v2: following referee's comments added some remarks and a subsection in the introduction, reorganized Section 2, modified some proofs and made some minor corrections, comments are welcome