Ingo Blechschmidt
Ingo Blechschmidt

Mathematician from Augsburg, Germany.

Enough injectives with just Zorn’s lemma and not the axiom of choice:
draft paper (see appendix)

2024 Verona Minicourse on extracting programs from proofs

HoTTEST 2023: slides (Agda code)

Herrsching 2023: slides

Niš: slides
Fischbachau: slides, Agda exercises
plenary
Slides for Brixen 2022: informal, plenary
Slides for Schlehdorf 2022
Slides for Dagstuhl 2021
Slides for Antwerp 2022
Slides for CiE 2022
Slides for CIRM 2023 (rough early draft of a preprint)

About me

I’m a mathematician working in applied topos theory. I obtained my PhD in October 2017 under the supervision of Marc Nieper-Wißkirchen at the University of Augsburg. Besides research, I love teaching mathematics at all levels and am passionate about doing mathematics with school students. Currently I’m back in Augsburg. During the academic year 2018/2019, I was working at the Università di Verona under the supervision of Peter Schuster. In the winter term 2017/2018, I was substituting a junior professor at the University of Augsburg, and during the summer of 2018, I was a guest at the Max Planck Institute for Mathematics in the Sciences in Leipzig.

I explore applications of the internal language of toposes, particularly in commutative algebra and in algebraic geometry.



I contribute to the nLab and to the Stacks Project, and encourage everyone to consider Eugenia Cheng’s manifesto for inclusivity in category theory and mathematics at large.

Recent results by Matthias Ritter (formerly Matthias Hutzler): The infinitesimal topos classifies the theory of quotients of local algebras by nilpotent ideals (master’s thesis), Syntactic presentations for glued toposes and for crystalline toposes (PhD thesis)

Recent result by Johannes Riebel: The undecidability of BB(748)

Travel plans

External mathematician vs. internal mathematician
Illustration: Carina Willbold (CC BY-SA)