  Does information play a significant role in the foundations of physics?
Information is the abstraction that allows us to refer to the states of systems
when we choose to ignore the systems themselves. This is only possible in very
particular frameworks, like in classical or quantum theory, or more generally,
whenever there exists an information unit such that the state of any system can
be reversibly encoded in a sufficient number of such units. In this work we
show how the abstract formalism of quantum theory can be deduced solely from
the existence of an information unit with suitable properties, together with
two further natural assumptions: the continuity and reversibility of dynamics,
and the possibility of characterizing the state of a composite system by local
measurements. This constitutes a new set of postulates for quantum theory with
a simple and direct physical meaning, like the ones of special relativity or
thermodynamics, and it articulates a strong connection between physics and
information.

Quantum Physics;General Relativity and Quantum Cosmology;High Energy Physics - Theory