Monday, 19 January, 2026
at Lise Meitner Lecture Hall, University of Vienna
Boltzmanngasse 5, 1090 Wien

Quantum mechanics based on real numbers: A consistent description

Complex numbers play a crucial role in quantum mechanics. However, their necessity remains debated: whether they are fundamental or merely convenient. Recently, it was claimed that quantum mechanics based on real numbers can be experimentally falsified in the sense that any real-number formulation of quantum mechanics either becomes inconsistent with multipartite experiments or violates certain postulates. We show that a physically motivated postulate about composite quantum systems allows to construct quantum mechanics based on real numbers that reproduces predictions for all multipartite quantum experiments. Thus, we argue that real-valued quantum mechanics cannot be falsified, and therefore the use of complex numbers is a matter of convenience.

Host: Beatrix Hiesmayr

You can follow this talk via zoom

Program

16:45 Get Together with Snacks

17:15 VCQ Student Talk

17:30 VCQ Colloquium Talk