Mathematisch-Physikalisches Kolloquium im Wintersemester 2022/2023

Wir möchten Sie auf das Mathematisch-Physikalische Kolloquium der Fakultät für Mathematik und Physik der Leibniz Universität Hannover hinweisen.

Am Dienstag, den 13.12.2022 um 16:30 Uhr spricht

PD Dr. Jonathan Bowden (Universität Regensburg)

in Hörsaal B302 zum Thema

Automorphisms of Surfaces

Abstract: The classification of compact topological surfaces goes back to the mid 19th century, in lieu of attempts to find counterexamples to Euler’s formulae for polyhedra, and is a landmark result in classical geometric topology. On the other hand the group of automorphisms of a surface is a very rich object and its study is still relevant today. The mapping class group of a surface, consisting of automorphisms up to deformation, appears naturally in many contexts Teichmüller theory, Thurston’s Geometrisation of 3-manifolds, stable homotopy theory (Madsen-Weiss’ proof of the Mumford Conjecture) to name a few. By contrast, the study of the full group of automorphisms, which is relevant in dynamics, is somewhat less understood and several natural questions remained open until recently. I will put these problems into context and indicate some recent progress concerning the geometry of this group in joint work with S. Hensel and R. Webb.

Am Dienstag, den 24.1.2023 um 16:30 Uhr spricht

Dr. Fabian Reede (Leibniz Universität Hannover)

in Hörsaal B302 zum Thema

New examples of stable bundles on hyperkähler manifolds of higher dimensions

(Antrittsvorlesung im Rahmen des Habilitationsverfahrens)

Abstract: Stable sheaves on K3 surfaces and their moduli spaces have been extensively studied. However, it is a challenging problem to construct non-trivial examples of stable sheaves on hyperkähler manifolds of higher dimensions let alone study their moduli spaces. In this talk I will present several constructions by applying techniques in derived categories which even produce irreducible components of the moduli spaces of such sheaves. This talk is based on joint work with Ziyu Zhang.