English

Crystalline liftability of irregular weights

Number Theory 2025-06-30 v1

Abstract

Let pp be an odd prime. Let K/QpK/\mathbb{Q}_p be a finite unramified extension. Let ρ:GKGL2(Fp)\rho: G_K \to GL_2(\overline{\mathbb{F}}_p) be a continuous representation. We prove that ρ\rho has a crystalline lift of small irregular weight if and only if it has multiple crystalline lifts of certain specified regular weights. The inspiration for this result comes from work of Diamond-Sasaki on geometric Serre weight conjectures. Our result provides a way to translate results currently formulated only for regular weights to also include irregular weights. The proof uses results on Kisin and (φ,G^)(\varphi,\hat{G})-modules obtained from extending recent work of Gee-Liu-Savitt to study crystalline liftability of irregular weights.

Keywords

Cite

@article{arxiv.2506.21637,
  title  = {Crystalline liftability of irregular weights},
  author = {Hanneke Wiersema},
  journal= {arXiv preprint arXiv:2506.21637},
  year   = {2025}
}

Comments

Comments welcome! arXiv admin note: text overlap with arXiv:1203.2552 by other authors