Geometry Seminar / Graduate Lectures
The Geometry seminar encompasses invited talks, Graduate Lectures of the Department of Mathematics as well as talks by Ph. D. students and theses defences. Upcoming events will be announced through the seminar's mailing list.
Everyone interested is welcome to attend.
Unless specified otherwise our seminar will take place at 13:30 in WIL C/104.
| 15.07.2025 (Tue) WIL C/104 13:30 |
Julian Weigert (MPI-MIS Leipzig) Geometry of polytopal adjoints |
| 08.07.2025 (Tue) WIL C/104 13:30 |
TBD |
| 01.07.2025 (Tue) WIL C/104 13:30 |
TBD |
| 24.06.2025 (Tue) WIL C/104 13:30 |
no seminar |
| 17.06.2025 (Tue) WIL C/104 13:30 |
Joris Koefler (MPI-MIS Leipzig) Taking the amplituhedron to the limit Abstract: The amplituhedron is a semi-algebraic set given as the image of the positive Grassmannian under a linear map subject to a choice of additional parameters. We define the limit amplituhedron as the limit of amplituhedra by sending one of the parameters to infinity. We derive its algebraic boundary in terms of Chow varieties and explain its geometric interpretation from the point of view of Positive Geometry in terms of secants of the rational normal curve. This discussion shows that the limit amplituhedron is a positive geometry with a unique differential form. |
|
10.06.2025 (Tue) |
no seminar |
| 03.06.2025 (Tue) WIL C/104 13:30 |
no seminar |
| 27.05.2025 (Tue) WIL C/104 13:30 |
no seminar |
| 20.05.2025 (Tue) WIL C/104 13:30 |
Thesis Defense: Kenan Vrabac (TU Dresden) Amenability of finite energy path and loop groups Abstract: Defense of the Master thesis |
| 20.05.2025 (Tue) WIL C/104 13:30 |
no seminar |
| 06.05.2025 (Tue) WIL C/104 13:30 |
Vukasin Stojisavljevic (CRM/UdeM - CNRS/Sorbonne) Nodal topology and topological data analysis Abstract: Classical Courant's nodal domain theorem provides an upper bound on the number of nodal domains of a Laplace-Beltrami eigenfunction in terms of its eigenvalue. It has long been known that direct generalizations of this theorem to linear combinations of eigenfunctions fail in general. By introducing the coarse count of nodal domains, based on topological data analysis, we will show a "coarse generalization" of the Courant's theorem. More precisely, we combine the theory of persistence modules and barcodes with the theory of Sobolev spaces in order to study oscillations of functions on different scales. As another application of the same method, we will prove a version of the classical Bézout's theorem for linear combinations of Laplace-Beltrami eigenfunctions. The talk is based on a joint work with L. Buhovsky, J. Payette, I. Polterovich, L. Polterovich and E. Shelukhin. |
| 29.04.2025 (Tue) WIL C/104 13:30 |
Fulvio Gesmundo (University of Paul Sabatier, Toulouse) Tensor networks, equations and geometry Abstract: Tensor network varieties are varieties of tensors arising from small tensors via certain contraction maps described combinatorially by a graph. They play a major role in quantum many-body physics as well as in other areas of applied mathematics, such as algebraic complexity theory and algebraic statistics. In this talk, I will discuss methods to construct equations of these varieties, based on classical intersection theory and invariant theory. |
| 22.04.2025 (Tue) WIL C/103 13:30 |
no seminar |
| 15.04.2025 (Tue) WIL C/103 13:30 |
no seminar |
For current lectures one can also refer to the Events calendar - Faculty of Mathematics.
The list of talks from past semesters can be found in the archive.