Address |
Mathematisches Institut, Universität Bonn Endenicher Allee 60 53115 Bonn Germany |
---|---|

Office | 4.006 |

lenz (at) math (dot) uni-bonn (dot) de | |

I’m a postdoc (*Akademischer Rat auf Zeit*) in the topology group
at the University of Bonn. Before that I was a postdoc at the University of Utrecht (2022–2024) and
at the University of Bonn (2021–2022), where I also obtained my PhD under the supervision of
Stefan Schwede in 2021.

My research concerns various aspects of homotopy theory, and I am particularly interested in questions relating to (parametrized) higher category theory, (global) equivariant homotopy theory, algebraic *K*-theory, and the interactions between these subjects.

**Normed Equivariant Ring Spectra and Higher Tambara Functors**

joint with Bastiaan Cnossen, Rune Haugseng, and Sil Linskens

preprint, 64 pages

arXiv:2407.08399**Parametrized (Higher) Semiadditivity and the Universality of Spans**

joint with Bastiaan Cnossen and Sil Linskens

preprint, 75 pages

arXiv:2403.07676**Homotopical Commutative Rings and Bispans**

joint with Bastiaan Cnossen, Rune Haugseng, and Sil Linskens

preprint, 34 pages

arXiv:2403.06911**The Adams Isomorphism Revisited**

joint with Bastiaan Cnossen and Sil Linskens

*Math. Z.***308**No. 2 (2024), Paper No. 33, 32 pages

published version arXiv:2311.04884**Simplicial *-Modules and Mild Actions**

joint with Anna Marie Schröter

*Homology Homotopy Appl.***26**No. 2 (2024), pp. 229–258

published version arXiv version (arXiv:2307.11002)**Partial Parametrized Presentability and the Universal Property of Equivariant Spectra**

joint with Bastiaan Cnossen and Sil Linskens

preprint, 56 pages

arXiv:2307.11001**Global Model Categories and Topological André-Quillen Cohomology**

joint with Michael Stahlhauer

to appear in*Trans. Amer. Math. Soc.*, 79 pages

arXiv:2302.06207**Parametrized Stability and the Universal Property of Global Spectra**

joint with Bastiaan Cnossen and Sil Linskens

preprint, 110 pages

arXiv:2301.08240**Genuine Versus Naïve Symmetric Monoidal***G*-Categories

*Doc. Math.***28**No. 5 (2023), pp. 1079–1161

published version arXiv version (arXiv:2203.02277)**Global Algebraic***K*-Theory is Swan*K*-Theory

preprint, 53 pages

arXiv:2202.07272**Categorical Models of Unstable***G*-Global Homotopy Theory

*Cah. Topol. Géom. Différ. Catég.***64**No. 4 (2023), pp. 439–481

published version arXiv version (arXiv:2109.02067)*G*-Global Homotopy Theory and Algebraic*K*-Theory

to appear in*Mem. Amer. Math. Soc.*, v + 246 pages

arXiv:2012.12676 presentation (Junior Mathematician Research Archive)**On the Global Homotopy Theory of Symmetric Monoidal Categories**

*New York J. Math.***29**(2023), pp. 635–686

published version arXiv version (arXiv:2009.07004)**Parsummable Categories as a Strictification of Symmetric Monoidal Categories**

*Theory Appl. Categ.***37**(2021), Paper No. 17, pp. 482–529

published version arXiv version (arXiv:2006.15068)**Homotopy (Pre)Derivators of Cofibration Categories and Quasicategories**

*Algebr. Geom. Topol.***18**No. 6 (2018), pp. 3601–3646

published version (doi:10.2140/agt.2018.18.3601) arXiv version (arXiv:1712.07845)

Assistant for lecture Topology I

taught by Stefan SchwedeAssistant for lecture Einführung in die Algebra

taught by Gebhard Martin

Lecture course Bewijzen in de Wiskunde (Proofs in Mathematics)

with Johan Commelin, Mireia Martínez i Sellarès, Lennart Meier, Guido Terra-Bleeker, and Marieke van der Wegen

Lecture course Selected Topics in Topology: Homotopy Coherent Algebraic Structures

Seminar Topologische Anwendungen algebraischer

*K*-Theorie (Applications of Algebraic*K*-Theory in Topology)

with Stefan Schwede

~~Together with Stefan Schwede I offer two topics for bachelor theses in the upcoming summer term. You can find more information about them in these slides.~~Both of these topics have been taken now.Graduate seminar Lie Groups and Their Representations

with Stefan SchwedeAssistant for the lecture Topology I

taught by Daniel Kasprowski