Welcome to my webpage. I am a postdoc in the working group of Prof. Chris Wendl at the Humboldt University Berlin.

From September 2014 till July 2018 I was a member of the working group of Prof. Hansjörg Geiges at the University of Cologne where I graduated in January 2017 about "Legendrian knots in surgery diagrams and the knot complement problem".

The fields of my research include low-dimensional topology, contact geometry, symplectic topology and their interactions.

**Mailing address:**

Institut für Mathematik

Humboldt-Universität zu Berlin

Unter den Linden 6

10099 Berlin

Germany

**Office:**

Rudower Chaussee 25 (Johann von Neumann-Haus)

12489 Berlin

Room : 318, Haus 1

Telephon : +49-30-2093-45426

E-Mails :

Office Hours: after the lectures

Lunch: daily at 11:30

- We will organize a one-day workshop at the Humboldt University Berlin about knot theory and its applications on Monday 9. December 2024. Berlin-Brandenburg Workshop IV: Knot Theory and its Application.

**Geometric topology:** low dimensional topology, experimental mathematics, knot theory, 3-manifolds, smooth 4-manifolds, Dehn surgery, open books, Kirby calculus,
Lefschetz fibrations, trisections and Heegaard splittings.

**Differential topology:** contact and symplectic geometry, Legendrian and transverse knot theory, Engel structures, Morse theory, hyperbolic geometry.

Exercise session for Topology II

Chun-Sheng Hsueh, Ph.D. student funded by the Claussen-Simon Stiftung.

Supervised master and bachelor students

Working group seminar on symplectic geometry

Berlin-Hamburg Seminar zur symplektischen Geometrie

Oberseminar Differentialgeometrie und Geometrische Analysis

Workshop on 4-manifolds and algorithms, University Regensburg, 9. Sep - 13. Sep 2024.

Berlin-Brandenburg Workshop III: Knot Theory and its Application, Friday, 17 May 2024.

Berlin-Brandenburg Workshop II: Knot Theory and its Application, Friday, 17 November 2023.

Berlin-Brandenburg Workshop I: Knot Theory and its Application, Friday, 14 July 2023.

DMV-Jahrestagung 2022, Section S06: Topology and Geometry, Freie Universität Berlin, September 2022.

Reading seminar: Freedman's proof of the 4-dimensional Poincaré conjecture, WS 2021/22

Learning Seminar: Computational Topology, WS 2017/18, University of Cologne

The stabilisation height of fibre surfaces, Lecture series by Filip Misev, 19 Oct - 20 Oct 2017, University of Cologne

Morse Structures on Open Books, Lecture series by Joan Licata, 17 May - 19 May 2017, University of Cologne

A video illustrating that Haken's knot is isotopic to the unknot. This was created for a lecture on Differential Topology.

Knoty a program to generate interactive 3D animations of Legedrian knots and contact structures. This program was written by Stanislaus Stein during a lecture on Contact Geometry.

Lecture notes for the lecture 4-Manifolds and Kirby calculus.

Lecture notes for the lecture Topology of 3-manifolds.

Carolin Wengler's notes for the lecture Topologie I.

Connect Four on the Klein bottle (Vier gewinnt auf der Kleinschen Flasche)

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