Gábor Hofer-Szabó (Hungarian Academy of Sciences): ‘Operational equivalence and causal structure’

This will be a hybrid lecture: you can attend in person in our usual LAK 2.06 seminar room, or on Zoom:

 Join On Zoom

Meeting ID: 852 3006 9457
Passcode: 297258

Abstract: In this talk, I will explore some consequences of abandoning operational equivalence in quantum mechanics. Two measurements are operationally equivalent if they yield the same distribution of outcomes in every quantum state and hence are represented by the same operator. I will show that the ontological models for quantum mechanics — and more generally, for any operational theory — sensitively depend on which measurement we choose from the class of operationally equivalent measurements. To this goal, I will take first three examples — a classical theory, the EPR-Bell scenario and the Popescu-Rochrlich box; then realize each example by two different operational theories — one with a trivial and another with a non-trivial compatibility structure; and finally compare the ontological models for the different theories with respect to their causal structure, contextuality, and fine-tuning.

Gábor Hofer-Szabó is a regular faculty member at the Research Center For The Humanities in Budapest.