Department of Mathematical Sciences
Universitetsparken 5, Building 4
2100 Copenhagen Ø
Office 04.4.03, bj(at)math.ku.dk

I am a third year PhD Student at the Copenhagen Centre for Geometry and Topology. My supervisor is Jesper Grodal.

Research Interest: Stable homotopy theory (equivariant, but recently also motivic), higher category theory

Current Projects: Some of the following projects are in a very early stage. Please get in contact with me if you want to know about details:

Equivariant recognition principle: I am aiming to prove a version of the recognition principle for representations which do not necessarily contain a trivial summand.

Algebraic K-theory of algebraic tori (joint with Bai, Carmeli, Riedel): Given an algebraic torus, by delooping the coweight lattice, one obtains a topological torus with an action of the Galois group. We identify the algebraic K-theory of the algebraic torus with the equivariant Bredon homology of the topological torus with coefficients the K-theory of the base field.

Geometric fixed points of global spectra (joint with Linskens): We aim to give a description of global spectra in terms of their geometric fixed points, i.e as a partially bilax limit.

Prepublications

[1] On orthogonal factorization systems and double categories, preprint, 2025

We prove that the ∞-category of orthogonal factorization systems embeds fully faithfully into the ∞-category of double ∞-categories. Moreover, we prove an (un)straightening equivalence for double ∞-categories, which restricts to an (un)straightening equivalence for op-Gray fibrations and curved orthofibrations of orthogonal factorization systems.

[2] Orbifolds, Orbispaces and Global Homotopy Theory, preprint, 2020.

My bachelor's thesis