Thomas Streicher

Thomas Streicher was an Austrian mathematician who was a Professor of Mathematics at Technische Universität Darmstadt. He received his PhD in 1988 from the University of Passau with advisor Manfred Broy.

Life and work

Streicher's research interests included categorical logic, domain theory and Martin-Löf type theory.
In joint work with he constructed a model for intensional Martin-Löf type theory where identity types are interpreted as groupoids. This was the first model with non-trivial identity types, i.e. other than sets. Based on this work other models with non-trivial identity types were studied, including homotopy type theory which has been proposed as a foundation for mathematics in Vladimir Voevodsky's research program Univalent Foundations of Mathematics.
Together with Martin Hofmann he received the 2014 IEEE Symposium on [Logic in Computer Science|LICS Test-of-Time Award] for the paper: The groupoid model refutes uniqueness of identity proofs.
Streicher died on 2 January 2025, at the age of 66.