English

The local lifting problem for A_4

Algebraic Geometry 2016-10-19 v2 Number Theory

Abstract

We solve the local lifting problem for the alternating group A_4, thus showing that it is a local Oort group. Specifically, if k is an algebraically closed field of characteristic 2, we prove that every A_4-extension of k[[s]] lifts to characteristic zero. As a consequence, every A_4-branched cover of smooth projective curves in characteristic 2 lifts to characteristic zero.

Cite

@article{arxiv.1602.01596,
  title  = {The local lifting problem for A_4},
  author = {Andrew Obus},
  journal= {arXiv preprint arXiv:1602.01596},
  year   = {2016}
}

Comments

Minor revisions, now 9 pages, to appear in Algebra and Number Theory

R2 v1 2026-06-22T12:43:23.653Z