Tobias Barthel

I am a W2 Research Group Leader at the Max Planck Institute of Mathematics in Bonn, interested in homotopy theory, tensor-triangular geometry, and their various interactions with other areas of mathematics. My work is supported by an ERC Starting Grant. I finished my PhD thesis under the supervision of Mike Hopkins in 2014, then spent the following years as a postdoc in Bonn as well as at the University of Copenhagen,  partly supported by an EU Marie Curie Individual Fellowship. 


Together with Paul Balmer, John Greenlees, Henning Krause, and Julia Pevtsova, we recently organized a HIM trimester program in Bonn on Spectral Methods in Algebra, Geometry, and Topology. More details are available on the webpage of the program.

List of preprints.

List of publications. 


Here is a video of me speaking about ultrachromatic homotopy theory at Ravenel's 70th birthday conference, Reed College, August 2017

The Transatlantic Transchromatic Homotopy Theory Workshop II

This was a five-day workshop on transchromatic homotopy theory in Regensburg, organized by Drew Heard, Niko Naumann, Nat Stapleton, and myself.  Due to the covid-19 pandemic, the main workshop had been postponed to August 2023. For more information, please see the workshop's homepage

The European Talbot Workshop

Together with Sean Tilson, we started the European Talbot Workshop in 2014. The current organizers are: Bertram Arnold,  Luciana Basualdo Bonatto, Jack Davies, and Alice Hedenlund.  


In 2018, I was involved in the organization of two Masterclasses in Copenhagen, together with Jesper Grodal and  Markus Hausmann.

In March 2017, Jesper Grodal and I organized a Masterclass on Stratifications and duality in modular representation theory

My collaborators: Ben Antieau, Omar Antolin-Camarena, Ko Aoki, Greg Arone, Scott Balchin, Dave Barnes, Miguel Barrero, Agnès Beaudry, Dave Benson, Dan Berwick-Evans, A.K. Bousfield, Shachar Carmeli, Natalia Castellana, Anish Chedalavada, Martin Frankland, David Gepner, Paul Goerss, Frank Gounelas, J.P.C. Greenlees, Jesper Grodal, Jeremy Hahn, Peter Haine, Markus Hausmann, Drew Heard, Gijs Heuts, Kaif Hilman, Joshua Hunt, Srikanth Iyengar, Bernhard Keller, Nikolay Konovalov, Achim Krause, Henning Krause, Peter May, Lennart Meier, Niko Naumann, Thomas Nikolaus, Justin Noel, Eric Peterson, Julia Pevtsova, Luca Pol, Piotr Pstragowski, Emily Riehl, Beren Sanders, Tomer Schlank, Nathaniel Stapleton, Greg Stevenson, Vesna Stojanoska, Neil Strickland, Gabriel Valenzuela, Marco Volpe, Jared Weinstein, Jordan Williamson, Lior Yanovski, Changhan Zou. 

The above image (Projet de clavier ultrachromatique, 1943) is taken from the book of writings by Wyschnegradsky (Libération du son: écrits 1916-1979, ed. Pascale Criton. Lyon: Symétrie 2013), Ivan Wyschnegradsky Collection, Paul Sacher Stiftung, Basel.