English

Realization of permutation modules via Alexandroff spaces

Algebraic Topology 2024-02-14 v3 Combinatorics Group Theory Representation Theory

Abstract

We raise the question of the realizability of permutation modules in the context of Kahn's realizability problem for abstract groups and the GG-Moore space problem. Specifically, given a finite group GG, we consider a collection {Mi}i=1n\{M_i\}_{i=1}^n of finitely generated ZG\Z G-modules that admit a submodule decomposition on which GG acts by permuting the summands. Then we prove the existence of connected finite spaces XX that realize each MiM_i as its ii-th homology, GG as its group of self-homotopy equivalences \E(X)\E(X), and the action of GG on each MiM_i as the action of \E(X)\E(X) on Hi(X;Z)H_i(X; \Z).

Keywords

Cite

@article{arxiv.2308.16675,
  title  = {Realization of permutation modules via Alexandroff spaces},
  author = {Cristina Costoya and Rafael Gomes and Antonio Viruel},
  journal= {arXiv preprint arXiv:2308.16675},
  year   = {2024}
}

Comments

14 pages, 3 figures, v3: first author's affiliation modified; grant for the second author added

R2 v1 2026-06-28T12:09:17.977Z