Time in Quantum Theory (TiQT) 2026

Session

Quantum Reference Frames

27 May 2026, 09:00

Albano 3: 4204 - SU Conference Room (56 seats) (Albano Building 3)

15. Some observations concerning the role of unsharp time observables as quantum reference frames

Prof. Leon Loveridge (University of South-Eastern Norway)

27/05/2026, 09:00

Invited Talk

The famous Pauli theorem rules out the possibility of time observables being represented by self-adjoint operators in physically realistic theories. Nevertheless, often time-translation covariant POVMs do exist. When used as quantum reference frames, such `non-ideality' is sometimes viewed as an inconvenience. In this talk, I will argue that in some settings it is an important feature - for...

7. Foundations of scalar relational quantum field theory

Mr Samuel Fedida (University of Cambridge)

27/05/2026, 09:40

Talk

We develop foundations for a relational approach to quantum field theory based on the operational quantum reference frames framework considered in a relativistic setting. Unlike other efforts in combining QFT with QRFs, we use the latter to provide novel mathematical and conceptual foundations for the former. We focus on scalar fields in Minkowski spacetime and discuss the emergence of...

18. Quantum limits of a space-time reference frame

Mr Davide Mattei (University of Rome, Tor Vergata)

27/05/2026, 10:00

Talk

We study the limitations for defining spatial and temporal intervals when the only available reference frame is a single composite quantum system, whose internal degrees of freedom serve as a temporal reference — a clock — and whose centre-of-mass degrees of freedom act as a spatial reference — a rod. By combining quantum speed limits with the mass–energy equivalence of special relativity, we...

2. Time delocalization and causality across temporal quantum reference frames

Dr Veronika Baumann (IQOQI Vienna)

27/05/2026, 11:00

Talk

In relational quantum dynamics, evolution emerges via the correlations between some system of interest and a clock system, which plays the role of a temporal reference frame. Their combined state satisfies a Wheeler-de Witt-like constraint equation, and therefore does not evolve, leading to a „block universe“ picture. I will talk about temporal localization and causal relations, when comparing...

5. Network of quantum reference frames and the nature of conservation laws in quantum mechanics

Dr Ismael Lucas de Paiva (Universidade Federal de Pernambuco)

27/05/2026, 11:20

Talk

In quantum theory, conservation laws are typically formulated at a statistical level, holding only on average across measurement outcomes. Recent work has shown that this limitation can be overcome in certain scenarios: by explicitly including the quantum reference frame associated with a system’s preparation, exact conservation can be recovered at the level of individual measurement outcomes....