English

A recognition theorem for permutation modules over $p$-groups extending Weiss' Theorem

Representation Theory 2025-11-26 v1

Abstract

Let GG be a finite pp-group with normal subgroup NN, and RR a complete discrete valuation ring in mixed characteristic. We characterize permutation RGRG-modules in terms of modules for RNRN and R[G/N]R[G/N]. The result generalizes both the seminal detection theorem for permutation modules due to Weiss, who characterizes those permutation RGRG-modules that are RNRN-free when RR is a finite extension of Zp\mathbb{Z}_p, and a more recent result of MacQuarrie and Zalesskii, who prove a characterization of permutation modules when NN has order pp and R=ZpR = \mathbb{Z}_p.

Keywords

Cite

@article{arxiv.2511.19710,
  title  = {A recognition theorem for permutation modules over $p$-groups extending Weiss' Theorem},
  author = {Marlon Estanislau},
  journal= {arXiv preprint arXiv:2511.19710},
  year   = {2025}
}
R2 v1 2026-07-01T07:53:11.062Z