Oberseminar Sommersemester 2026

Die Vorträge finden jeweils donnerstags um 16:45 Uhr im Raum WSC-N-U-3.05 (im Mathematikgebäude ) statt.
Der Tee findet ab 16:15 in Raum O-3.46 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. Before the talk, at 4:15pm, there is tea in room O-3.46.
Everybody who’s interested is welcome to join.

Directions from the train station.

16.04.2026	Marta Pieropan (Utrecht)	Campana points and firmaments
23.04.2026	reserved	t.b.a.
30.04.2026	N.N.	t.b.a.
07.05.2026	Luca Francone (Rome)	t.b.a.
21.05.2026	N.N.	t.b.a.
28.05.2026	N.N.	t.b.a.
11.06.2026	Ben Moonen (Nijmegen)	t.b.a.
18.06.2026	N.N.	t.b.a.
25.06.2026	Baptiste Calmès (Lens)	t.b.a.
02.07.2026	Joshua Jackson (Cambridge)	t.b.a.
09.07.2026	Aryaman Patel (Saarbrücken)	The Hitchin morphism over higher-dimensional base manifolds
16.07.2026	N.N.	t.b.a.
23.07.2026	N.N.	t.b.a.

Abstracts

Marta Pieropan: Campana points and firmaments

Determining the image of the set of rational points under a morphism of varieties is a very natural and difficult question. The case where the morphism is geometrically surjective has been studied extensively. From Campana’s theory of orbifolds, it follows that over a number field, the image of the set of rational points is contained in the set of Campana points for the orbifold base of the morphism. This first approximation of the image of the set of rational points is refined by Abramovich’s theory of firmaments. This talk presents some arithmetic questions about Campana points, and a proof of a claim by Abramovich about lifting firm points under toroidal morphisms in joint work with Herr, Mehidi and Poiret.