Publications Teaching Topology group

Tobias Lenz

Address
Mathematisches Institut, Universität Bonn
Endenicher Allee 60
53115 Bonn
Germany
Office 4.006
E-mail 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.

Publications and preprints

  1. Normed Equivariant Ring Spectra and Higher Tambara Functors
    joint with Bastiaan Cnossen, Rune Haugseng, and Sil Linskens
    preprint, 64 pages
    arXiv:2407.08399

  2. Parametrized (Higher) Semiadditivity and the Universality of Spans
    joint with Bastiaan Cnossen and Sil Linskens
    preprint, 75 pages
    arXiv:2403.07676

  3. Homotopical Commutative Rings and Bispans
    joint with Bastiaan Cnossen, Rune Haugseng, and Sil Linskens
    preprint, 34 pages
    arXiv:2403.06911

  4. 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

  5. Simplicial *-Modules and Mild Actions
    joint with Anna Marie Schröter
    Homology Homotopy Appl. 26 No. 2 (2024), pp. 229–258
    published versionarXiv version (arXiv:2307.11002)

  6. Partial Parametrized Presentability and the Universal Property of Equivariant Spectra
    joint with Bastiaan Cnossen and Sil Linskens
    preprint, 56 pages
    arXiv:2307.11001

  7. Global Model Categories and Topological André-Quillen Cohomology
    joint with Michael Stahlhauer
    to appear in Trans. Amer. Math. Soc., 79 pages
    arXiv:2302.06207

  8. Parametrized Stability and the Universal Property of Global Spectra
    joint with Bastiaan Cnossen and Sil Linskens
    preprint, 110 pages
    arXiv:2301.08240

  9. Genuine Versus Naïve Symmetric Monoidal G-Categories
    Doc. Math. 28 No. 5 (2023), pp. 1079–1161
    published version arXiv version (arXiv:2203.02277)

  10. Global Algebraic K-Theory is Swan K-Theory
    preprint, 53 pages
    arXiv:2202.07272

  11. 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)

  12. G-Global Homotopy Theory and Algebraic K-Theory
    to appear in Mem. Amer. Math. Soc., v + 246 pages
    arXiv:2012.12676presentation (Junior Mathematician Research Archive)

  13. 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)

  14. 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)

  15. 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)

Teaching

University of Bonn

Winter 2024/25

University of Utrecht

Fall 2023

University of Bonn

Summer 2022

Winter 2021/22