Any consistent coupling between classical gravity and quantum matter is fundamentally irreversible

TD Galley, F Giacomini, JH Selby - Quantum, 2023 - quantum-journal.org
When gravity is sourced by a quantum system, there is tension between its role as the
mediator of a fundamental interaction, which is expected to acquire nonclassical features …

Which theories have a measurement problem?

N Ormrod, V Vilasini, J Barrett - arxiv preprint arxiv:2303.03353, 2023 - arxiv.org
It is shown that any theory that has certain properties has a measurement problem, in the
sense that it makes predictions that are incompatible with measurement outcomes being …

Testing quantum theory with thought experiments

N Nurgalieva, R Renner - Contemporary Physics, 2020 - Taylor & Francis
Quantum mechanics is one of our most successful physical theories; its predictions agree
with experimental observations to an extremely high accuracy. However, the bare formalism …

A refined Frauchiger--Renner paradox based on strong contextuality

L Walleghem, RS Barbosa, M Pusey… - arxiv preprint arxiv …, 2024 - arxiv.org
The Frauchiger--Renner paradox derives an inconsistency when quantum theory is used to
describe the use of itself, by means of a scenario where agents model other agents …

A general framework for consistent logical reasoning in Wigner's friend scenarios: subjective perspectives of agents within a single quantum circuit

V Vilasini, MP Woods - arxiv, 2022 - research-collection.ethz.ch
It is natural to expect a complete physical theory to have the ability to consistently model
agents as physical systems of the theory. In [Nat. Comms. 9, 3711 (2018)], Frauchiger and …

Classical Information and Collapse in Wigner's Friend Setups

V Baumann - Entropy, 2023 - mdpi.com
The famous Wigner's friend experiment considers an observer—the friend—and a
superobserver—Wigner—who treats the friend as a quantum system and her interaction with …

Extended Wigner's friend paradoxes do not require nonlocal correlations

L Walleghem, R Wagner, Y Yīng, D Schmid - arxiv preprint arxiv …, 2023 - arxiv.org
Extended Wigner's friend no-go theorems provide a modern lens for investigating the
measurement problem, by making precise the challenges that arise when one attempts to …

Improvements on Device Independent and Semi-Device Independent Protocols of Randomness Expansion

R Bhavsar - arxiv preprint arxiv:2311.13528, 2023 - arxiv.org
To generate genuine random numbers, random number generators based on quantum
theory are essential. However, ensuring that the process used to produce randomness …

A no-go theorem for absolute observed events without inequalities or modal logic

N Ormrod, J Barrett - arxiv preprint arxiv:2209.03940, 2022 - arxiv.org
This paper builds on no-go theorems to the effect that quantum theory is inconsistent with
observations being absolute; that is, unique and non-relative. Unlike the existing no-go …

Toys can't play: physical agents in Spekkens' theory

L Hausmann, N Nurgalieva, L del Rio - New Journal of Physics, 2023 - iopscience.iop.org
Abstract Information is physical (Landauer 1961 IBM J. Res. Dev. 5 183–91), and for a
physical theory to be universal, it should model observers as physical systems, with concrete …