Oberseminar SoSe 24

Die Vorträge finden jeweils donnerstags um 16:45 Uhr im Raum WSC-N-U-3.05 (im Mathematikgebäude ) statt. Directions from the train station.
Der Tee findet ab 16:15 statt.

Alle Interessenten sind herzlich eingeladen!

The seminar takes place on Thursday, starting at 4:45pm. The duration of each talk is about 60 minutes.
Everybody who’s interested is welcome to join.

11.4.2024 Yukako Kezuka (Paris) Non-vanishing results for some CM elliptic curves
18.4.2024 Irene Spelta (Barcelona) Special subvarieties of the Torelli locus: examples
25.4.2024 Alex Küronya (Frankfurt) Structures on cohomology and P=W for abelian varieties
2.5.2024 N. N. tba
16.5.2024 Mihai Pavel (Bukarest) Variation of moduli of sheaves in higher dimensions
23.5.2024 Stefano Marseglia (University of French Polynesia) tba
6.6.2024 reserviert
13.6.2024 Quentin Posva (Düsseldorf) tba
20.6.2024 (Guido Kings, tbc) tba
27.6.2024 Symposium Düsseldorf/Essen/Wuppertal
4.7.2024 Mario Kummer (TU Dresden) tba
11.7.2024 Alexander Petrov (IAS) tba
18.7.2024 Michael Thaddeus (Columbia) tba

Abstracts

Yukako Kezuka: Non-vanishing results for some CM elliptic curves

We prove non-vanishing results for the values at $s=1$ of the complex L-series of quadratic twists of the elliptic curves with complex multiplication introduced by B. Gross in his thesis. From this, we obtain the finiteness of their Tate–Shafarevich group. For a prime $\mathfrak P$ lying above the prime 2, we also prove a $\mathfrak P$-converse theorem in the rank 0 case for the higher-dimensional abelian varieties obtained by restriction of scalars.

Irene Spelta: Special subvarieties of the Torelli locus: examples

The Torelli morphism $j \colon \mathcal M_g \to \mathcal A_g$ associates to an algebraic curve $C$ its Jacobian $J_C$ (as a principally polarized abelian variety). Very classically, it is injective on geometric points. In this talk, we will discuss the interplay between the geometry of $\mathcal M_g$ and of $\mathcal A_g$. In particular, we will consider certain special subvarieties. We will explain how this is linked to a conjecture by Coleman and Oort, and we will analyse explicit examples.

Alex Küronya: Structures on cohomology and P=W for abelian varieties

The purpose of this talk is to discuss the significance of various extra structures on the (co)homology of algebraic varieties, leading to a discussion of the recent P=W conjecture and its verification for abelian varieties.

Mihai Pavel: Variation of moduli of sheaves in higher dimensions

We introduce a notion of semistability for coherent sheaves over a projective manifold, which is well-behaved from the perspective of variation in higher dimensions. Specifically, we obtain (new) moduli spaces of semistable pure sheaves, along with a locally finite wall-chamber structure that governs their variation with the change of semistability. This involves showing uniform boundedness statements for semistable pure sheaves.