collaborators

6 papers

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.AC2025

The Tate Intermediate Value Theorem

Paul Balmer, Beren Sanders

We explain how the gluing of a closed piece of the tensor-triangular spectrum with its open complement hinges on the support of the Tate ring.

math.AC2024

Perfect complexes and completion

Paul Balmer, Beren Sanders

Let be the -adic completion of a commutative ring with respect to a finitely generated ideal . We give a necessary and sufficient criterion for the category of…

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,…