Research Seminar

The research Seminar offers an opportunity to present latest research results or to discuss topics from the area of differential geometry (and nearby areas) which are of general interest to our institute.

Students are very welcome to attend!

We mostly meet on Thursdays at 14:00 in LUH in B302, Welfengarten 1 . Check the schedule for exceptions, expecially during the first two weeks!!

Summer semester 2023

This semester we are repeating the successful format from last semester of our research seminar. It will be a common seminar between all members of our institute. The idea is to introduce an advanced topic, from the point of view of students, and try to motivate the postdocs and PhD students (or whoever wants) to find common research problems of interest.

The goal of the research seminar is to present several (non-compact) explicit examples of manifolds with Ricci-flat Kaehler metrics or hyperkaehler metrics. Apart from being ”general knowledge” examples, several of these spaces play two important roles in differential geometry. They can serve as building blocks of more complicated, compact spaces (e.g. the Kummer construction of K3 surfaces and Joyce’s construction of G2 manifolds). These explicit examples are also often of interest on their own, since they are both sufficiently simple to serve as tractable model spaces, but also non-trivial enough to be interesting.

Each talk has suggested sources, but the speaker is of course free to deviate from or completely ignore these.


Are you  interested in this seminar? If you want to give a talk e-mail Renan Assimos or Joergen Lye (better both), even if the topic you would like to speak about is already taken by a postdoc; the postdoc in charge of the talk will instead be happy to tutor you thoughout your preparation.

EVERY STUDENT is really encouraged to come, regardless of their background in Geometry or in Analysis. 

**** Be aware of the intense first two weeks, we will cover some basics more than once a week so we can start talking about interesting stuff right on the second week of the semester.

**** Note that not every talk will assume knowledge of previous talks. So if you missed a couple of weeks, still give it a try. Talk to a postdoc!

Organizers: the postdocs


Summer semester 2023

For abstracts, please add your email to the seminars mailing list (e-mail Joergen Lye to be added).

10.05.2023 12:15-13:45
Giuseppe Gentile
(Leibniz Universität Hannover)


03.05.2023 12:15-13:45
Joergen Lye
(Leibniz Universität Hannover)

Minimal submanifolds.

27.04.2023 16:30-17:30
Guadalupe Catillo-Solano
(Universität Regensburg)

Title: The Moduli space of Ricci-flat metrics on a K3 surface.

Abstract: It is known that if M is a compact spin manifold, then the moduli
space of Ricci-flat metrics modulo the action of the diffeomorphism group
is a smooth manifold of finite dimension. In this talk, we consider M to be a
carefully constructed K3 surface and outline an argument showing that in
this case, the moduli space is not complete. 

27.04.2023 15:00-16:00
Alejandro Gil Garcia
(Universität Hamburg)

Title: A class of locally inhomogeneous complete quaternionic Kähler manifolds.

Abstract: We prove that the one-loop deformation of any quaternionic Kähler manifold
in the class of c-map spaces is locally inhomogeneous. As a corollary, we obtain that the
full isometry group of the one-loop deformation of any homogeneous c-map space has
precisely cohomogeneity one.
This is a joint work with Vicente Cortés and Arpan Saha (

26.04.2023 12:15-13:45
(Leibniz Universität Hannover)

The Stenzel metric on Tangent Bundle of Spheres.

20.04.2023 14:15-15:45
Joergen Lye
(Leibniz Universität Hannover)

Calabi’s two families of examples.

19.04.2023 12:15-13:45
Renan Assimos
(Leibniz Universität Hannover)

Monge-Ampe`re on ALE spaces.

14.04.2023 14:15-15:45
Nikolaos Eptaminitakis
(Leibniz Universität Hannover)

Finding Calabi-Yau metrics - the Monge-Ampe`re route.

13.04.2023 14:15-15:45
Yuguang Zhang
(Leibniz Universität Hannover)

More Ka ̈hler geometry and special holonomy.

11.04.2023 14:15-15:45
Joergen Lye
(Leibniz Universität Hannover)

Basics of (hyper-)Kähler geometry and special holonomy.



Winter semester 2022/23

19.01.2023 14:15-15:15 Nikolaos Eptaminitakis
(Leibniz Universität Hannover)
Long time behavior for solutions of the mean curvature flow.
12.01.2023 14:15-15:15 Renan Assimos
(Leibniz Universität Hannover)
The Lagrangian Mean Curvature Flow
15.12.2022 14:15-15:15 Prof. Knut Smoczyk
(Leibniz Universität Hannover)
The geometry of Lagrangian submanifolds in Kähler-Einstein manifolds
08.12.2022 14:15-15:15 Jorgen Olsen Lye
(Leibniz Universität Hannover)
Calibrated geometries and Lagrangian submanifolds
01.12.2022 14:15-15:15 Jorgen Olsen Lye
(Leibniz Universität Hannover)
Kähler manifolds and introduction to calibrations
17.11.2022 14:15-15:15 Philipp Grunwald
(Leibniz Universität Hannover)
Evolution equations
27.10.2022  14:15-15:15 Giuseppe Gentile
(Leibniz Universität Hannover)
Sections 1 and 2 (until Simons' eq.)
20.10.2022 14:15-15:15 Giuseppe Gentile
(Leibniz Universität Hannover)

Notation, reviewing the basics:

 connections on bundles, pullback connections, etc...



Summer semester 2022

21.04.2022 14:15-15:15 Jorgen Olsen Lye
(Leibniz Universität Hannover)
02.06.2022 14:15-15:15 Lothar Schiemanowski
(Leibniz Universität Hannover)
Topology of special holonomy asymptotically conical manifolds
23.06.2022 14:15-15:15 Lynn Heller
(Leibniz Universität Hannover)

Loop group methods for the non-abelian Hodge correspondence on a 4-punctured sphere


Winter semester 2021/22

04.11.2021 14:15-15:15 Sebastian Heller
(Leibniz Universität Hannover)
Parabolic bundles and DPW potentials
18.11.2021 14:15-15:15 Roger Bielawski
(Leibniz Universität Hannover)
Coulomb branch and W-Hilbert schemes
02.12.2021 14:15-14:45 Yuguang Zhang
(Leibniz Universität Hannover)
Exercises of scalar curvatures on symplectic 4-manifolds
13.01.2022 14:15-15:15 Sebastian Heller
(Leibniz Universität Hannover)
Spin structures and Projective structures on Riemann surfaces
27.01.2022 14:15-15:15 Giuseppe Gentile
(Leibniz Universität Hannover)
On the prescribed mean curvature flow of graphs in certain Lorentzian manifolds with non-compact space-like slice


Summer semester 2021

22.04.2021 14:15-15:15 Sebastian Heller
(Leibniz Universität Hannover)
Willmore spheres in the 3-sphere revisited
29.04.2021 14:15-15:15 No Talk  
06.05.2021 14:15-15:15 No Talk (Annual Staff Briefing)  
13.05.2021 14:15-15:15 Holiday  
20.05.2021 14:15-15:15

Max Schult
(Leibniz Universität Hannover)

The Penrose construction
27.05.2021 14:15-15:15 Pentecost Break  
03.06.2021 14:15-15:15

Andreas Savas-Halilaj
(University of Ioannina)

Minimal maps, MCF and isotopy problems
10.06.2021 14:15-15:15 Lynn Heller 
(Leibniz Universität Hannover)
Holomorphic connections on the trivial bundle  with Fuchsian monodromy
17.06.2021 14:15-15:15 Sebastian Heller 
(Leibniz Universität Hannover)
SYZ Geometry and the Y-vertex
24.06.2021 14:15-15:15 Daniel Fadel 
(Peking University)
Large mass monopoles on asymptotically conical 3-manifolds
01.07.2021 14:15-15:15 Renan Assimos 
(Leibniz Universität Hannover)
Building classical harmonic maps borrowing ideas from harmonic graphs
08.07.2021 14:15-15:15 no seminar  
15.07.2021 14:15-15:15

Lothar Schiemanowski
(Leibniz Universität Hannover)

Introduction to the spinor flow
22.07.2021 14:15-15:15

Balázs Békési
(Leibniz Universität Hannover)



Winter semester 2020/2021

15.10.2020 14:15-14:45 Schiden Yohannes
(Leibniz Universität Hannover)
The Sasaki-Ricci flow
22.10.2020 14:15-15:15 Knut Smoczyk
(Leibniz Universität Hannover)
Self-expanders of the mean curvature flow
29.10.2020 14:15-15:15 Thomas Raujouan
(Leibniz Universität Hannover)
Construction of complete embedded CMC surfaces in space forms
5.11.2020 14:15-15:15 Lothar Schiemanowski
(Leibniz Universität Hannover)
Riemannian manifolds with L^p curvature bounds and their limit spaces
12.11.2020 14:15-15:15 Renan Assimos
(Leibniz Universität Hannover)
On a spherical Bernstein theorem by B. Solomon
19.11.2020 14:15-15:15 Yuguang  Zhang
(Leibniz Universität Hannover)
Some observations of general type hypersurfaces in CP³
26.11.2020 14:15-15:15 Sebastian Heller
(Leibniz Universität Hannover)
Abelianisation of flat connections
10.12.2020 14:15-15:15 Norman Zergänge
(Leibniz Universität Hannover)
Aspects of Riemannian manifolds with integral curvature bounds
17.12.2020 14:15-15:15 Andreas Savas-Halilaj
(University of Ioannina)
Curve shortening flow on Riemann surfaces
14.01.2021 14:15-15:15 Naizhen Zhang
(Leibniz Universität Hannover)
Degenerations of Grassmannians, quiver representations and Bruhat-Tits theory
21.01.2021 14:15-15:15 Roger Bielawski
(Leibniz Universität Hannover)
Deformations of hyperkaehler cones
28.01.2021 14:15-15:15 Lynn Heller
(Leibniz Universität Hannover)

Complete families of embedded high genus CMC surfaces in the 3-sphere


Winter semester 2019/2020

07.11.2019 14:15-15:45 Sebastian Heller
(Leibniz Universität Hannover)
The energy of holomorphic sections of the Deligne-Hitchin moduli space
21.11.2019 14:15-15:45 Naizhen Zhang
(Leibniz Universität Hannover)
The Strong Maximal Rank Conjecture and higher rank Brill–Noether theory


Summer semester 2019

11.04.2019 14:15-15:45 Roger Bielawski
(Leibniz Universität Hannover)
The differential geometry of Hilbert schemes of curves in projective spaces
16.05.2019 14:15-15:45 Lynn Heller
(Leibniz Universität Hannover)
Isotherme constrained Willmore Tori in der 3 Sphäre
23.05.2019 14:15-15:45 Monty-Max. Zuehlke
(Leibniz Universität Hannover)
Short-time existence and uniqueness of a conformal Willmore flow on closed, non-isothermic surfaces
18.07.2019 14:15-15:45 Oliver Sonderegger
(Leibniz Universität Hannover)
Hyperkähler metrics on regular nilpotent adjoint orbits