About me

I am assistant professor in the Department of Mathematics at Radboud University Nijmegen.

My primary area of research is algebraic topology. I am also interested in questions about algebraic K-theory, higher category theory, derived algebraic geometry, and homological algebra.


email address
Phone: +31 24 365 2296

HG03.735, Huygensgebouw, Heyendaalseweg 135, 6525 AJ Nijmegen

Postal address
Steffen Sagave, Radboud Universiteit, IMAPP - Mathematics, PO Box 9010, 6500 GL Nijmegen, The Netherlands



Spring semester 2018/19
Master Seminar (together with Stefanie Sonner)
Course description, times and brightspace page

Teaching in previous terms


  1. Homotopical and operator algebraic twisted K-theory
    (joint with Fabian Hebestreit)
    arXiv:1904.01872, pdf-file
  2. Multiplicative parametrized homotopy theory via symmetric spectra in retractive spaces
    (joint with Fabian Hebestreit and Christian Schlichtkrull)
    arXiv:1904.01824, pdf-file
  3. A strictly commutative model for the cochain algebra of a space
    (joint with Birgit Richter)
    arXiv:1801.01060, pdf-file
  4. Comparing cyclotomic structures on different models for topological Hochschild homology
    (joint with Emanuele Dotto, Cary Malkiewich, Irakli Patchkoria and Calvin Woo)
    arXiv:1707.07862, pdf-file

Publications and accepted papers

(in reverse chronological order of acceptance)

  1. Virtual vector bundles and graded Thom spectra
    (joint with Christian Schlichtkrull)
    Mathematische Zeitschrift (2018), 1-42, doi:10.1007/s00209-018-2131-0
    arXiv:1410.4492, pdf-file, published article
  2. Generalized Thom spectra and their topological Hochschild homology
    (joint with Samik Basu and Christian Schlichtkrull)
    Journal of the Institute of Mathematics of Jussieu (2017), 1-44, doi:10.1017/S1474748017000421
    arXiv:1608.08388, pdf-file, published article
  3. Presentably symmetric monoidal infinity-categories are represented by symmetric monoidal model categories
    (joint with Thomas Nikolaus)
    Algebraic & Geometric Topology, 17 (2017), 3189–3212.
    arXiv:1506.01475, pdf-file, published article
  4. Logarithmic topological Hochschild homology of topological K-theory spectra
    (joint with John Rognes and Christian Schlichtkrull)
    Journal of the European Mathematical Society (JEMS), 20 (2018), no. 2, 489–527.
    arXiv:1410.2170, pdf-file, published article
  5. Topological Hochschild homology and the cyclic bar construction in symmetric spectra
    (joint with Irakli Patchkoria)
    Proceedings of the American Mathematical Society, 144 (2016), no. 9, 4099–4106.
    arXiv:1508.03129, pdf-file, published article
  6. Spectra of units for periodic ring spectra and group completion of graded E-infinity spaces
    Algebraic & Geometric Topology, 16 (2016), 1203–1251.
    arXiv:1111.6731, pdf-file, published article
  7. Localization sequences for logarithmic topological Hochschild homology
    (joint with John Rognes and Christian Schlichtkrull)
    Mathematische Annalen, 363 (2015), no. 3, 1349–1398.
    arXiv:1402.1317, pdf-file, published article
  8. Strictly commutative models for E-infinity quasi-categories
    (joint with Dimitar Kodjabachev)
    Homology, Homotopy and Applications, 17 (2015), no. 1, 121–128.
    arXiv:1408.0116, pdf-file, published article
  9. Derived logarithmic geometry I
    (joint with Timo Schürg and Gabriele Vezzosi)
    Journal of the Institute of Mathematics of Jussieu, 15 (2016), no. 2, 367–405.
    arXiv:1307.4246, pdf-file, published article
  10. Logarithmic structures on topological K-theory spectra
    Geometry & Topology, 18 (2014), 447–490.
    arXiv:1204.0699, pdf-file, published article
  11. Group completion and units in I-spaces
    (joint with Christian Schlichtkrull)
    Algebraic & Geometric Topology, 13 (2013), 625–686.
    arXiv:1111.6413, pdf-file, published article
  12. Diagram spaces and symmetric spectra
    (joint with Christian Schlichtkrull)
    Advances in Mathematics, 231 (2012), 2116–2193.
    arXiv:1103.2764, pdf-file, published article
  13. DG-algebras and derived A-infinity algebras
    Journal für die reine und angewandte Mathematik (Crelle's Journal), 639 (2010), 73–105.
    arXiv:0711.4499, pdf-file, published article
  14. Universal Toda brackets of ring spectra
    Transactions of the American Mathematical Society, 360 (2008), no. 5, 2767–2808.
    arXiv:math/0611808, pdf-file, published article
  15. On the algebraic K-theory of model categories
    Journal of Pure and Applied Algebra, 190 (2004), no. 1–3, 329–340.
    pdf-file, published article

Notes from talks

Usually, I give blackboard talks. Presentations from occasions where I used a projector can be found below. Moreover, this list contains a few extended abstracts and a link to a video of a talk.

© 2019 Steffen Sagave
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