Seminare und Vorträge im WS 2025/2026
| Date | Lecturer | Seminar | Theme | Time | Location |
|---|---|---|---|---|---|
| 14 Jul 2026 | Ryu Tomonaga (The University of Tokyo) | Auslander correspondence for higher stable dg categories and Amiot's conjecture Abstract: The notion of d-stable dg categories was introduced as an axiomatization of d-cluster tilting subcategories of stable dg categories. In this talk, we establish an Auslander correspondence for d-stable dg categories: for a given connective additive dg category M, we give an equivalent condition for M to be d-stable in terms of its derived category. As an application, we give a new proof of a variant of Amiot's conjecture, originally proved by Keller-Liu. | Tuesday, 3pm Time Zone Berlin, Rome, Paris in person | Stefan Cohn-Vossen Raum (Nr. 313 on floor 3) | |
| 21 Jul 2026 | Mika Jäderberg (Linköpings Universitet) | A Functor Between Cluster Categories Abstract: The (higher) cluster categories of hereditary algebras of type A have a geometric description in terms of diagonals in a regular polygon. Under certain numerical conditons, two different cluster categories are represented by the same polygon, which induces an embedding on objects from one cluster category into the other. The main question is whether this embedding can be promoted to a triangle functor between the cluster categories. To achive this, we will consider a particular dg-model of the derived category in which it becomes easy to both construct the desired functor and prove that it satisfies the equivariance condition required to induce a well-defined functor between the cluster categories. | Tuesday, 3pm Time Zone Berlin, Rome, Paris in person | Stefan Cohn-Vossen Raum (Nr. 313 on floor 3) | |
| 28 Jul 2026 | Judith Marquardt (Université Grenoble Alpes) | Degenerations of chain complexes Abstract: Riedtmann and Zwara have characterized degenerations of orbits in module varieties in terms of certain short exact sequences. In this talk, we study degenerations of orbits in varieties of chain complexes of projective modules. We show that degenerations are characterized in terms of certain admissible short exact sequences in the exact category of complexes of projectives. We then extend our study to the homotopy category. In this context, complexes of projectives with a given g-vector form an ind-variety, and we prove that degenerations of orbits are characterized using distinguished triangles in the category. This links to an algebraic definition of degeneration for triangulated categories introduced by Jensen, Su and Zimmermann. | Tuesday, 3pm Time Zone Berlin, Rome, Paris in person | Stefan Cohn-Vossen Raum (Nr. 313 on floor 3) | |