activity
20242026
collaborators

7 papers

math.RT2026

Permutation, stabilization and decomposition

Paul Balmer, Martin Gallauer

Informed by our understanding of the tt-geometry of permutation modules, we investigate the proper definition of the `stable permutation category' of a finite group. Then we prove…

math.CT2025

Periods in equivariant and motivic contexts

Martin Gallauer

We define the period as a multiplicative characteristic of stably symmetric monoidal -categories, develop its basic properties, and study many examples, with a focus on `or…

math.RT2025

The geometry of permutation modules

Paul Balmer, Martin Gallauer

We consider the derived category of permutation modules for a finite group, in positive characteristic. We stratify this tensor triangulated category using Brauer quotients. We des…

math.RT2025

The tt-geometry of permutation modules. Part I: Stratification

Paul Balmer, Martin Gallauer

We consider the derived category of permutation modules over a finite group, in positive characteristic. We stratify this tensor triangulated category using Brauer quotients. We de…

math.CT2025

Patch-density in tensor-triangular geometry

Paul Balmer, Martin Gallauer

The spectrum of a tensor-triangulated category carries a compact Hausdorff topology, called the constructible topology, also known as the patch topology. We prove that patch-dense…

math.AG2024

The spectrum of Artin motives

Paul Balmer, Martin Gallauer

We analyze the tt-geometry of derived Artin motives, via modular representation theory of profinite groups. To illustrate our methods, we discuss Artin motives over a finite field,…