Seminar Geometrie / Graduate Lectures
Im Rahmen des Seminars "Geometrie" finden Vorträge von Gästen des Instituts, Graduate Lectures der Fakultät für Mathematik zu aktuellen Themen, sowie Vorträge der Doktorand*innen und Verteidigungen von Abschlussarbeiten der Studierenden statt. Anstehende Termine werden über die Mailing-Liste des Seminars bekanntgegeben.
Alle Interessent*innen sind herzlich eingeladen.
Sofern nicht anders angegeben findet unser Seminar Dienstags um 13:30 in WIL C/103 statt.
| 03.02.2026 (Di) Raum: WIL C 103 13:30 |
Vadim Alekseev (TU Dresden) Sofic actions, halo products, and metric approximations of groups In this joint work with Henry Bradford, we introduce the notion of a sofic action of one group on another by automorphisms relative to a class C of groups. We show that for the classes of (i) sofic, (ii) hyperlinear, (iii) linear sofic or (iv) weakly sofic groups, respective class is closed under taking semidirect products with sofic C-action. We use this to construct a wide variety of new examples of groups in the respective classes, many of them arising as "halo products'' in the sense of Genevois-Tessera, as well as new examples of semidirect products which are locally embeddable into finite groups. |
| 27.01.2026 (Di) Raum: TBD 13:30 |
|
| 20.01.2026 (Di) Raum: WIL C/103 13:30 |
Lior Alon (MIT) C0⊃C1⊃. . .⊃C∞⊃analytic⊃trigonometric polynomials, and the decay of Fourier coefficients precisely reflects this hierarchy. In particular, the Fourier transform ^f has finite support if and only if f is a trigonometric polynomial. p(e2πix1, . . . , e2πixn), where p is a Lee--Yang polynomial. |
| 13.01.2026 (Di) Raum: TBD 13:30 |
|
| 06.01.2026 (Di) Raum: TBD 13:30 |
|
| 16.12.2025 (Di) Raum: TBD 13:30 |
|
| 09.12.2025 (Di) Raum: TBD 13:30 |
|
| 02.12.2025 (Di) Raum: TBD 13:30 |
|
| 25.11.2025 (Di) Raum: TBD 13:30 |
|
| 18.11.2025 (Di) Raum: TBD 13:30 |
|
| 11.11.2025 (Di) Raum: WIL C 103 13:30 |
Florian Frick (Carnegie Mellon University, Pittsburgh) Title: Geometry of Rips complexes and applications Abstract: In geometric group theory, Rips complexes give higher structure to a Cayley graph, while in computational topology they provide a natural thickening of a point sample. I will explain a construction that is closely related to Rips complexes, which is amenable to the tools of metric geometry. By recording the interaction of pairwise proximal points, low-dimensional objects are endowed with higher structure. As a consequence, one can derive bounds for Gromov-Hausdorff distances between spaces, constraints for the distribution of roots of certain zero-mean real-valued functions, and generalizations of the Borsuk-Ulam theorem. I will focus on surveying some of these applications. |
Für weitere Vorträge der Fakultät siehe auch Veranstaltungskalender Mathematik.
Eine Übersicht über Vorträge vergangener Semester ist im Archiv zu finden.