Home » Veranstaltungen

Kommende Vorträge

Posted in

Ausführliche Liste aller demnächst stattfindenden Vorträge und Seminare. Für eine Übersicht konsultieren Sie bitte auch den Kalender.

Oberseminar Arithmetic Geometry and Representation Theory

Posted in
Organiser(s): 
Prof. Dr. J. Fintzen, Prof. Dr. T. Kaletha, Prof. Dr. P. Scholze
Datum: 
Fre, 11/10/2024 - 14:05 - Fre, 19/12/2025 - 16:00
Location: 
MPIM Lecture Hall
Details: 
Program and Abstracts of Oberseminar Arithmetic Geometry and Representation Theory

https://people.mpim-bonn.mpg.de/scholze/veranstaltungen.html

Positivity of Gromov simplicial volume of non-positively curved 4-manifolds.

Posted in
Speaker: 
Inkang Kim
Zugehörigkeit: 
KIAS/MPIM
Datum: 
Mon, 14/07/2025 - 14:00 - 15:00
Location: 
MPIM Lecture Hall
Parent event: 
MPIM Topology Seminar

We show that a closed non-positively curved 4-manifold with negative Ricci curvature has positive Gromov's simplicial volume.

Metric ribbon graphs

Posted in
Speaker: 
Ivan Yakovlev
Zugehörigkeit: 
MPIM
Datum: 
Die, 15/07/2025 - 11:00 - 12:00
Location: 
MPIM Lecture Hall
Parent event: 
Low-dimensional topology seminar

Metric ribbon graphs (MRG) are graphs embedded into surfaces equipped with positive edge lengths. Functions counting MRG's with given boundary lengths are a priori piecewise polynomials, but in some cases become honest polynomials.

I will first present one such case -- Kontsevich's polynomials counting trivalent MRG's (from his proof of Witten's conjecture about intersection numbers on the moduli spaces of curves), and explain how they are used to study hyperbolic and flat surfaces.

Sharp mixed moment bounds for zeta times a Dirichlet L-function

Posted in
Speaker: 
Markus Hagen
Zugehörigkeit: 
NTNU
Datum: 
Die, 15/07/2025 - 16:30 - 17:30
Location: 
MPIM Lecture Hall
Parent event: 
PLeaSANT (Participative Learning Seminar on Any Number Theory)

A famous theorem of Selberg asserts that $\log|\zeta(\tfrac12+it)|$ is approximately a normal distribution with mean $0$ and variance $\tfrac12\log\log T$, when we sample $t\in [T,2T]$ uniformly.

Condensable Topological Defects in 4D Dijkgraaf-Witten models—Classification of Fusion 2-Categorical Symmetries

Posted in
Speaker: 
Hao Xu
Zugehörigkeit: 
Göttingen
Datum: 
Mit, 16/07/2025 - 10:30 - 12:00
Location: 
MPIM Lecture Hall
Parent event: 
Higher Differential Geometry Seminar

Given a finite group $G$ a 4-cocycle $\pi \in \mathrm{H}^4(G,U(1))$, the 4D Dijkgraaf–Witten model provides an exactly solvable gauge theory with applications in high-energy physics and topological phases of matter. The topological defects in this model form a braided fusion 2-category $\mathscr{Z}(\mathbf{2Vect}^\pi_G)$, the Drinfeld center of $\pi$-twisted $G$-crossed finite semisimple linear categories.

Hyperbolic Counting and Equidistribution

Posted in
Speaker: 
Marios Voskou
Zugehörigkeit: 
MPIM
Datum: 
Mit, 16/07/2025 - 14:30 - 15:30
Location: 
MPIM Lecture Hall
Parent event: 
Number theory lunch seminar

In Euclidean space, the Gauss Circle Problem concerns estimating the number of lattice points inside a Euclidean circle. In this talk, we examine analogous problems in the hyperbolic plane, approached through the lens of the spectral theory of automorphic forms. We also highlight arithmetic applications, particularly the distribution of ideals in number fields.

Khovanov skein lasagna modules with 1-dimensional inputs

Posted in
Speaker: 
Qiuyu Ren
Zugehörigkeit: 
UC Berkeley
Datum: 
Don, 17/07/2025 - 11:00 - 12:00
Location: 
MPIM Lecture Hall
Parent event: 
Low-dimensional topology seminar
Skein lasagna modules (with 0-dimensional inputs) are 4-manifold invariants introduced by Morrison-Walker-Wedrich. In this context, a skein is a properly embedded surface in a 4-manifold minus a disjoint union of 4-balls, and the lasagna comes from a TQFT for links in S^3 (satisfying mild conditions).

Degeneration of Kähler polarisations associated to imaginary-time flow

Posted in
Speaker: 
Dan Wang
Zugehörigkeit: 
MPIM
Datum: 
Don, 17/07/2025 - 15:00 - 16:00
Location: 
MPIM Lecture Hall
Parent event: 
MPI-Oberseminar

Geometric quantization on symplectic manifolds plays an important role in representation theory and mathematical physics, and is deeply related to symplectic and differential geometry. A crucial problem is to understand the relationships among geometric quantizations associated with different polarizations. In this talk, we will discuss the existence of mixed polarizations and degeneration of Kähler polarizations associated to imaginary-time flow.

Zero entropy on entire Grauert tubes

Posted in
Speaker: 
Pablo Suarez-Serrato
Zugehörigkeit: 
UNAM/MPIM
Datum: 
Don, 17/07/2025 - 16:30 - 17:00
Location: 
MPIM Lecture Hall
Parent event: 
Summer Geometry Day

On Fixed-Point Sets of $\Z_2$-Tori in Positive Curvature

Posted in
Speaker: 
Catherine Searle
Zugehörigkeit: 
Wichita State University/MPIM
Datum: 
Don, 17/07/2025 - 17:00 - 17:30
Location: 
MPIM Lecture Hall
Parent event: 
Summer Geometry Day

In recent work of Kennard, Khalili Samani, and the last author, they generalize the Half-Maximal Symmetry Rank result of Wilking for torus actions on positively curved manifolds to $\mathbb{Z}_2$-tori with a fixed point. They show that if the rank is approximately one-fourth of the dimension of the manifold, then fixed point set components of small co-rank subgroups of the $\Z_2$-torus  are homotopy equivalent to spheres, real projective spaces, complex projective spaces, or lens spaces.

© MPI f. Mathematik, Bonn Impressum & Datenschutz
-A A +A