The Leo Apostel Centre invites everyone to the 61th of its interdisciplinary seminars in the Foundations series. In this series CLEA invites scholars that are actively engaged in the research on the foundations of a particular discipline. Their lectures will always be directed to an interdisciplinary audience, and the discussions aim at confronting the foundations of the different disciplines.

Thursday December 20, 2007, 18u00-19u00, VUB, room D.2.19

Reinterpreting Quantum Probabilities in an Objective Framework: The Modified BCHSH Inequalities.

Speaker: Dr. Sandro Sozzo, University of Salento (Italy)

Abstract: Most physicists uphold that the tests of the Bell inequalities (BI) performed up to now confirm the predictions of standard quantum mechanics (SQM) and refute local realism. But some scholars criticize this conviction, defending local realism in various ways. We present here a new viewpoint based on the extended semantic realism (ESR) model that has been recently worked out in Lecce. The ESR model embodies the mathematical formalism of SQM into a more general framework in which objectivity of physical properties, hence local realism, holds, and the probabilities of SQM are reinterpreted as conditional instead of absolute. As a consequence, the ESR model provides some predictions that differ from those of SQM. In particular, we show that the BI introduced by Clauser, Horne, Shimony and Holt (BCHSH inequalities) must be replaced by modified BCHSH inequalities. These depend on detection probabilities which may be such that the new inequalities are never violated by the conditional expectation values predicted by the model. The condition that no violation occurs implies the existence of upper bounds on detection probabilities, which makes the ESR model falsifiable.

Sandro Sozzo studied physics at the University of Lecce where he graduated in 2002. He got his PhD in physics at the same University in 2006, discussing a thesis entitled: "Lecce and Brussels: Two proposals for a Realistic and Objective Interpretation of Quantum Mechanics". At present he is a postdoctoral fellow at the University of Salento. His research interests range from theoretical physics to philosophy of science, foundations of quantum mechanics, quantum logic. He was co-editor (with C. Garola and A. Rossi) of the volume "The Foundations of Quantum Mechanics: Historical Analysis and Open Questions", proceedings of the Conference "I Fondamenti della Meccanica Quantistica: Analisi Storica e Problemi Aperti", held in Cesena (Italy) in 2004, of which he was co-organizer.