Adán Cabello | LIP6 - Équipe QI

Adán Cabello - Beyond Bell: Testing the physical significance of non-locality

Tue, 20 Jan 2026 00:00:00 +0000

Beyond Bell: Testing the physical significance of non-locality

Ce séminaire, donné par Adán Cabello, aura lieu le 20 January 2026, à 13:0. Il aura lieu en salle 25-26/105.

Vous trouverez un plan du campus ici.

Résumé

In the formulation of Jarrett and Shimony, Bell inequalities follow from three assumptions: measurement independence (MI), parameter independence (PI), and outcome independence (OI). We have recently demonstrated that the conflict between quantum theory and hidden variables extends far beyond Bell’s theorem. Quantum theory violates inequalities even when MI and PI are simultaneously and arbitrarily relaxed (except for a complete relaxation), as well as inequalities where OI is arbitrarily relaxed (again, except completely). We will discuss the implications, experimental tests, and potential applications of these results.

Logical possibilities for physics after MIP*=RE

Sun, 17 Sep 2023 00:00:00 +0000

MIP*=RE implies that C_{qa} (the closure of the set of tensor product correlations) and C_{qc} (the set of commuting correlations) can be separated by a hyperplane (i.e., a Bell-like inequality) and that there are correlations produced by commuting measurements (a finite number of them and with a finite number of outcomes) on an infinite-dimensional quantum system which cannot be approximated by sequences of finite-dimensional tensor product correlations. We point out that there are four logically possible universes after this result. Each possibility is interesting because it reveals either limitations in accepted physical theories or opportunities to test crucial aspects of nature. We list some open problems that may help us to design a road map to learn in which of these universes we are.

Space QUEST mission proposal: Experimentally testing decoherence due to gravity

Tue, 12 Jun 2018 00:00:00 +0000

Models of quantum systems on curved space-times lack sufficient experimental verification. Some speculative theories suggest that quantum properties, such as entanglement, may exhibit entirely different behavior to purely classical systems. By measuring this effect or lack thereof, we can test the hypotheses behind several such models. For instance, as predicted by Ralph and coworkers [T C Ralph, G J Milburn, and T Downes, Phys. Rev. A, 79(2):22121, 2009, T C Ralph and J Pienaar, New Journal of Physics, 16(8):85008, 2014], a bipartite entangled system could decohere if each particle traversed through a different gravitational field gradient. We propose to study this effect in a ground to space uplink scenario. We extend the above theoretical predictions of Ralph and coworkers and discuss the scientific consequences of detecting/failing to detect the predicted gravitational decoherence. We present a detailed mission design of the European Space Agency’s (ESA) Space QUEST (Space - Quantum Entanglement Space Test) mission, and study the feasibility of the mission schema.