3 papers
gr-qc2025
The thermodynamics of readout devices and semiclassical gravity
Samuel Fedida, Adrian Kent
We analyse the common claim that nonlinear modifications of quantum theory necessarily violate the second law of thermodynamics. We focus on hypothetical extensions of quantum theo…
quant-ph2025
Einstein causality of quantum measurements in the Tomonaga-Schwinger picture
Samuel Fedida
We investigate a generalisation to Lüders' rule à la Aharonov-Albert in those globally hyperbolic spacetimes which allow unitarily equivalent Hilbert spaces to be defined along Cau…
gr-qc2024
Mixture equivalence principles and post-quantum theories of gravity
Samuel Fedida, Adrian Kent
We examine the mixture equivalence principle (MEP), which states that proper and improper mixed states with the same density matrix are always experimentally indistinguishable, and…