In 1986, Ghirardi, Rimini, and Weber proposed a scheme of theories, now known as GRW theories, as precise versions of quantum mechanics. In GRW theories, the vague and ambiguous ‘measurement axiom’ of ordinary quantum mechanics is replaced by precise laws governing the collapse of the wave function. The particular theory that I will focus on in my talk, the GRW flash theory, corresponds to a particular choice of the ontology now known as the flash ontology that was introduced by Bell in 1987. This theory achieves, as does Bohmian mechanics, what was considered impossible by the founding fathers of quantum mechanics: to provide an explanation of non-relativistic quantum mechanics in terms of an objective reality. This theory removes all mysteries and paradoxes, solves the measurement problem, and treats ‘observers’ as just another set of particles governed by the same laws as all other particles. In 2004, a relativistic version of the GRW flash theory was developed for N non-interacting spin-1/2 particles, a situation in which, however, already the tension between relativity and quantum non-locality comes up. I will elucidate the remarkably simple resolution of that tension in the GRW flash theory. In 2006, Conway and Kochen published what they call the ‘free will theorem’ and claimed that, as a corollary of their theorem, relativistic GRW theories are impossible. I will elucidate (a) the contents of the free will theorem, (b) why the relativistic GRW flash theory is a counter-example to their further claim, and (c) what is wrong with the reasoning behind their further claim.
Goldstein, Tausk, Tumulka, and Zaghi: 'What Does the Free Will Theorem Actually Prove?'
Tumulka: 'Comment on "The Free Will Theorem"'
Tumulka: 'Collapse and Relativity'
Tumulka: 'A Relativistic Version of the Ghirardi-Rimini-Weber Theory'
Conway and Kochen: 'The Strong Free Will Theorem'
Conway and Kochen: 'Reply to Comments of Bassi, Ghirardi, and Tumulka on the Free Will Theorem'