Bastiaan Cnossen

About

I am a post doc at the University of Regensburg, in the working group of Marc Hoyois. My mathematical interests lie in algebraic topology, homotopy theory and higher category theory. More specifically, I'm thinking about (global) equivariant homotopy theory, homotopy theory of differentiable stacks, parameterized category theory, twisted ambidexterity/Costenoble-Waner duality, and norm/transfer maps.

I am an associated member of the SFB 1085 "Higher Invariants".

I finished my PhD in September 2023 at the University of Bonn under the supervision of Stefan Schwede.

 Publications and preprints


7. Parametrized higher semiadditivity and the universality of spans 

Joint with Tobias Lenz and Sil Linskens.

Preprint, March 2024, arXiv:2403.07676.


6. Homotopical commutative rings and bispans 

Joint with Rune Haugseng, Tobias Lenz and Sil Linskens.

Preprint, March 2024, arXiv:2403.06911.


5. The Adams isomorphism revisited

Joint with Tobias Lenz and Sil Linskens.

Preprint, November 2023, arXiv:2311.04884.


4. Partial parametrized presentability and the universal property of equivariant spectra

Joint with Tobias Lenz and Sil Linskens.

Preprint, July 2023, arXiv:2307.11001.


3. Twisted ambidexterity in equivariant homotopy theory

Preprint, March 2023, arxiv:2303.00736.


2. Parameterized stability and the universal property of global spectra

Joint with Tobias Lenz and Sil Linskens.

Preprint, January 2023, arxiv:2301.08240.


1. Characters and transfer maps via categorified traces

Joint with Shachar Carmeli, Maxime Ramzi and Lior Yanovski

Preprint, October 2022, arXiv:2210.17364. 



PhD Dissertation: Twisted ambidexterity in equivariant homotopy theory: Two approaches


Teaching

Summer term 2024: Lie groups and representation theory 

Events

Together with Benjamin Dünzinger and Kevin Li, I am organizing this year's Bavarian Geometry and Topology Meeting XII, which takes place 8-9 April 2024 at the University of Regensburg.

Contact

Email: bastiaan.cnossen (add @ur.de)

Notes

Lecture notes from Cisinski's course ``Formalization of Higher Categories'' (an older version that includes the theory of tribes may be found here.)

Various expository notes