I am a postdoc at the University Bielefeld, Germany, in the BIREP group.

In 2020 I finished my PhD at the University of Utah. There I studied commutative algebra with Srikanth Iyengar. The title of my thesis is Generation Time in Derived Categories.

I obtained a Bachelor in Mathematics in 2014 and a Bachelor in Physics in 2015 from the Johannes Gutenberg University Mainz, Germany.

I am interested in triangulated, derived, and stable categories.

Here is my CV.


  1. Locally Complete Intersection Maps and the Proxy Small Property with Ben Briggs, Srikanth Iyengar, Josh Pollitz
    in International Mathematics Research Notices, pages 1–28, 2021. Advance article
  2. Local to global principles for generation time over Noether algebras
    in Homology, Homotopy and Applications, 23(2): 165–182, 2021

Current and Upcoming

Part of the FDLIST Team
The FDLIST is a network for research in representation theory of finite-dimensional algebras and related topics. It provides a platform for the exchange of information, ideas, problems and questions.
Organizing the internal seminar of the BIREP group
Bielefeld University—Summer semester 2021
Workshop on Homotopy Theory and Group Theory (IRP Higher Homotopical Structures)
Barcelona, Spain, hyprid—July 5–9, 2021
I will give an online talk titled Homotopical characterization of exceptional complete intersection maps, which is joint work with Srikanth Iyengar, Jian Liu, and Josh Pollitz.
Together with Allechar Serrano López, Christian Klevdal, Peter McDonald and Sabine Lang I am organizing the conference BRIDGES for June 16–18, 2021. This conference is aimed towards early graduate students and advanced undergraduate students interested in representation theory, number theory, and commutative algebra.
Organizing the conference Representation Theory and Triangulated Categories
This is a conference in honour of Henning Krause's 60th birthday. I am one of the organizers together with Dave Benson, Bill Crawley-Boevey, Eleonore Faber, Lutz Hille, Srikanth Iyengar, and Marc Stephan. The conference will take place on September 26–30, 2022 in Bielefeld.

Past talks.
Past conferences.
Past position, activities and resources.


jletz [at] math [dot] uni-bielefeld [dot] de
Mailing Address
Faculty of Mathematics
Bielefeld University
PO Box 100 131
33501 Bielefeld