The Role of Information in the Foundations of Physics

Despite the enormous success of quantum theory, its significance and meaning are still being debated. In particular, the standard postulates of quantum theory are abstract mathematical statements in terms of complex vectors, self adjoint operators, etc., and as such they lack any direct physical meaning. For this reason, it is difficult to assess what these postulates say about the structure of the physical world. Lluis Masanes (formerly at ICFO, now in Bristol) together with Remigiusz Augusiak from the Quantum Optics Theory Group led by ICREA Professor at ICFO Maciej Lewenstein, and colleagues from Waterloo and Madrid have proven that quantum theory can be formulated through four very simple postulates, each having a direct physical and intuitive meaning. One of these postulates establishes the existence of an information unit, capable of simulating the physics of any other type of system. This unveils the important role that information plays in the foundations of physics.