English

On the Inertia Conjecture and its generalizations

Algebraic Geometry 2023-03-29 v1

Abstract

Studying two point branched Galois covers of the projective line we prove the Inertia Conjecture for the Alternating groups Ap+1A_{p+1}, Ap+3A_{p+3}, Ap+4A_{p+4} for any odd prime p2(mod3)p \equiv 2 \pmod{3} and for the group Ap+5A_{p+5} when additionally 4(p+1)4 \nmid (p+1) and p17p \geq 17. We obtain a generalization of a patching result by Raynaud which reduces these proofs to showing the realizations of the \'{e}tale Galois covers of the affine line with a fewer candidates for the inertia groups above \infty. We also pose a general question motivated by the Inertia Conjecture and obtain some affirmative results. A special case of this question, which we call the Generalized Purely Wild Inertia Conjecture, is shown to be true for the groups for which the purely wild part of the Inertia Conjecture is already established. In particular, we show that if this generalized conjecture is true for the groups G1G_1 and G2G_2 which do not have a common quotient, then the conjecture is also true for the product G1×G2G_1 \times G_2.

Keywords

Cite

@article{arxiv.2002.04934,
  title  = {On the Inertia Conjecture and its generalizations},
  author = {Soumyadip Das},
  journal= {arXiv preprint arXiv:2002.04934},
  year   = {2023}
}

Comments

25 pages

R2 v1 2026-06-23T13:39:28.063Z