Possibility in quantum mechanics

OLIMPIA LOMBARDI

Córdoba

Congreso; VII Conference on Quantum Foundations: 90 Years of Uncertainty; 2017

FAMAF, Unversidad Nacional de Córdoba

On the basis of the assumption that the quantum state codifiesprobabilities, and that probability measures possibility, the examination ofthe nature of quantum possibility turns out to be essential in the discussionsabout the interpretation of quantum mechanics.Here I will recall the two two general conceptions of possibility,both of which find their roots in Antiquity, and I will argue that only one ofthem is the proper conception for quantum mechanics. From this viewpoint, apropensity is the tendency of a possible to become actual, and probabilitiesare measures of propensities.On the other hand, I will argue that, once possibility is soconceived, quantum mechanics does not require a generalized concept ofprobability. Probabilities can be conceived as second-order properties thatapply to the properties represented by the observables of the system. But Kolmogorovianprobabilities are sufficient since propensities arise in each context, and thesimultaneous assignment of propensities to observables belonging to differentcontexts makes no sense.