Welcome by the Royal Society and Gerardo Adesso
Professor Gerardo Adesso, University of Nottingham
Recovering the quantum formalism from physically realist axioms
Professor Philippe Grangier, Insitute d'Optique Palaiseau
We present a heuristic derivation of Born's rule and unitary transforms in Quantum Mechanics, from a simple set of axioms built upon a physical phenomenology of quantisation. This approach naturally leads to the usual quantum formalism, within a new realistic conceptual framework that is discussed in details. Physically, the structure of Quantum Mechanics appears as a result of the interplay between the quantised number of "modalities" accessible to a quantum system, and the continuum of "contexts" that are required to define these modalities. Mathematically, the Hilbert space structure appears as a consequence of a specific "extra-contextuality" of modalities, closely related to the hypothesis of Gleason's theorem, and consistent with its conclusions.
Relational quantum mechanics: understanding with 'relations' versus understanding with 'things'
Professor Carlo Rovelli, Aix-Marseille University
Quantum automata field theory: derivation of mechanics from algorithmic principles
Professor Giacomo Mauro D'Ariano, University of Pavia
This talk will briefly review a recent derivation of quantum theory and free quantum field theory from purely information-theoretical principles, leading to an extended theory made with quantum walks. We will focus on the causality principle for quantum theory, and show that its notion coincides with the usual Einstein’s one in special relativity. It will then see how Lorentz transformations are derived from just our informational principles, without using space-time, kinematics, and mechanics. The Galileo relativity principle is translated to the case of general dynamical systems. The resulting invariance group is a nonlinear version of the Lorentz group (the automata theory is thus a model for the so-called "doubly special relativity"), and the usual linear group is recovered in the small wavevector regime, corresponding to the physical domain experimented so far. The notion of particle is still that of Poincaré invariant. New interesting emerging features arise that have a General-Relativity flavour.
Complementarity and uncertainty: what remains?
Professor Reinhard F Werner, Leibniz University of Hannover
Complementarity and uncertainty were two ideas in the early development of quantum mechanics. Famously, Bohr and Heisenberg introduced them separately, after they took a break from a series of intense discussions in Copenhagen in 1927. They both worked at a rather heuristic level, and public presentations of their ideas still tend to reflect this early style and the sense of paradox, which the original authors cherished so much.
On the other hand, also in 1927, the theory took mathematical shape at the hands of von Neumann, which made wave particle dualism obsolete, and opened up the possibility of turning the heuristic ideas of Heisenberg and Bohr into general, quantitative and falsifiable statements. For uncertainty this process also began in 1927, when Kennard and Weyl fulfilled Heisenberg's promise that the uncertainty relations could be proved from the basic assumptions of the theory. The disturbance-accuracy tradeoff took much longer, but is today also firmly established.
The role of complementarity changed in a general process of sharpening of interpretation. Today the operational content of quantum mechanics and its statistical framework is very clear. It can be applied and taught with confidence without taking recourse to Bohr's elaborate complementary doublethink. Yet the old idea still has an important if somewhat demystified place. In the talk this place will be pointed out and some continuity with origins established.