7 papers
Are free choices absolute, when internalized in Wigner's friend?
Laurens Walleghem
Wigner's thought experiment illustrates quantum theory's measurement problem by considering an observer who measures a quantum system inside a sealed lab, modeled unitarily by an o…
Particle detector in a position-superposed black hole spacetime
Laurens Walleghem, Carlo Cepollaro
We calculate the response of an Unruh--DeWitt detector in a 2+1d spacetime that contains a BTZ black hole in a superposition of locations as viewed in a reference system associated…
Wigner's friend's black hole adventure: an argument for complementarity?
Laurens Walleghem
At the heart of both black hole physics and Wigner's friend scenarios lies the question of unitarity. In Wigner's friend setups, sealed-lab measurements are modeled unitarily, prob…
An extended Wigner's friend no-go theorem inspired by generalized contextuality
Laurens Walleghem, Lorenzo Catani
The renowned Local Friendliness no-go theorem demonstrates the incompatibility of quantum theory with the combined assumptions of Absoluteness of Observed Events - the idea that ob…
Connecting extended Wigner's friend arguments and noncontextuality
Laurens Walleghem, Yìlè Yīng, Rafael Wagner +1
The Local Friendliness argument is an extended Wigner's friend no-go theorem that provides strong constraints on the nature of reality -- stronger even than those imposed by Bell's…
A refined Frauchiger--Renner paradox based on strong contextuality
Laurens Walleghem, Rui Soares Barbosa, Matthew F. Pusey +1
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 quantumly…