Paolo PERINOTTI

Abstract : In this seminar we will review the efforts towards a reformulation of quantum theory from operational axioms that stemmed from the experience of quantum information theory. Starting with the early two thousands, a handful of new approaches appeared. We will discuss their main traits, and focus on the Pavia approach. This one lead to a formulation in terms of six postulates, and is characterised by two aspects: the first one is the rigorous formulation of a framework of possible theories, among which the quantum one is singled out—the framework of Operational Probabilistic Theories (OPTs); the second one is the central role played by purification, the only pustulate out of six which is not satisfied by the theory of classical systems, and can thus be easily identified as the quintessentially quantum feature of the theory. We will close the seminar with a discussion of recent developments.