I am a fourth year PhD student at the Mathematical Institute of the University of Bonn under the supervision of Carl-Friedrich Bödigheimer, in the area of algebraic topology. I am funded by the Max Planck Institute for Mathematics in Bonn and am a member of the International Max Planck research school (IMPRS) on moduli spaces.

### Research interests

My PhD project deals with coloured topological operads and their algebras, configuration spaces, and the phenomenon of homological stability, as well as mapping class groups, moduli spaces of Riemann surfaces and their homology.

More recently, I have been studying low-dimensional equivariant and parametrised cobordism categories and their homotopy type.

My co-authors are Andrea Bianchi from the University of Copenhagen and Jens Reinhold from the University of Münster.

### Teaching

In the summer term 2020, I co-organised a graduate seminar on Operads in Algebra and Topology together with Andrea Bianchi. Moreover, I have been tutor for the following topology lectures:

 summer 2021 Algebraic Topology 2 Carl-Friedrich Bödigheimer winter 2020/21 Algebraic Topology 1 Carl-Friedrich Bödigheimer summer 2020 Algebraic Topology 2 Christoph Winges winter 2019/20 Algebraic Topology 1 Wolfgang Lück summer 2019 Topology 2 Daniel Kasprowski winter 2018/19 Topology 1 Wolfgang Lück summer 2018 Geometrie und Topologie Wolfgang Lück

### Preprints

• #### Parametrised moduli spaces of surfaces as infinite loop spaces

12/05/2021, arXiv:2105.05772, with Andrea Bianchi and Jens Reinhold

We study the E2-algebra $$\Lambda\mathfrak{M}$$ consisting of free loop spaces of moduli spaces of Riemann surfaces with one parametrised boundary component, and compute the homotopy type of the group completion $$\Omega B\Lambda\mathfrak{M}$$: it is the product of $$\Omega^\infty\mathbf{MTSO}(2)$$ with a certain free $$\Omega^\infty$$-space depending on the family of all boundary-irreducible mapping classes in all mapping class groups $$\Gamma_{g,n}$$ with $$g\geqslant 0$$ and $$n\geqslant 1$$.

• #### Configuration spaces of clusters as Ed-algebras

06/04/2021, arXiv:2104.02729

It is a classical result that configuration spaces of labelled particles in $$\mathbb{R}^d$$ are free algebras over the little $$d$$-cubes operad, and their d-fold bar construction is equivalent to the $$d$$-fold suspension of the labelling space. The aim of this paper is to study a variation of these spaces, namely the configuration space of labelled clusters of points in $$\mathbb{R}^d$$. This configuration space is again an Ed-algebra, but in general not a free one. We give geometric models for their iterated bar construction in two different ways: one uses an additional verticality constraint, and the other one uses a description of these clustered configuration spaces as cellular E1-algebras. In the last section, we show a stable splitting result and present some applications.

• #### Vertical configuration spaces and their homology

22/03/2021, arXiv:2103.12137, with Andrea Bianchi

We introduce ordered and unordered configuration spaces of ‘clusters’ of points in an Euclidean space $$\mathbb{R}^d$$, where points in each cluster have to satisfy a ‘verticality’ condition, depending on a decomposition $$d=p+q$$. We compute the homology in the ordered case and prove homological stability in the unordered case.

• #### Moduli spaces of Riemann surfaces and symmetric products: A combinatorial description of the Mumford–Miller–Morita classes

25/09/2018, PDF (911 kiB)

This is my master’s thesis which was finished in the summer term 2018. Its main result is a Poincaré–Lefschetz correspondene between the Mumford–Miller–Morita classes in the cohomology of moduli spaces and certain simplicial subcomplexes of Bödigheimer’s model of parallel slit domains.

### Selected talks

• #### Homotopy coherent multiplications and loop spaces

05/11/2020, PDF (1.1 MiB)

These are the notes of a talk I gave in the winter term 2020/21 in our IMPRS seminar at the MPI. They tell a classical story about H-spaces, loop spaces, and May’s recognition principle.

• #### An introduction to model categories

10/06/2020, PDF (1.3 MiB)

In summer 2020, the first ‘corona term’, I gave an introductory talk on model categories in our IMPRS seminar. It was the first in a series of four talks and essentially covers the first chapter of Hovey’s book on the topic.

Contact details

Mathematical Institute
Office 4.020
Endenicher Allee 60
53115 Bonn
Germany

PGP Public Key (0xD2890F65)

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