Permutation modules and cohomological singularity
arXiv:2009.14093 · doi:10.4171/cmh/534
Abstract
We define a new invariant of finitely generated representations of a finite group, with coefficients in a commutative noetherian ring. This invariant uses group cohomology and takes values in the singularity category of the coefficient ring. It detects which representations are controlled by permutation modules.
arXiv comment14 pages; v2: new introduction, shorter discussion of `big' triangulated categories; v3: minor changes before publication