Physics as Information Processing

I review some recent advances in foundational research at Pavia QUIT group. The gen- eral idea is that there is only Quantum Theory without quantization rules, and the whole Physics— including space-time and relativity–is emergent from the quantum-information processing. And since Quantum Theory itself is axiomatized solely on informational principles, the whole Physics must be reformulated in information-theoretical terms: this is the It from bit of J. A. Wheeler. The review is divided into four parts: a) the informational axiomatization of Quantum Theory; b) how space-time and relativistic covariance emerge from quantum computation; c) what is the information-theoretical meaning of inertial mass and of h ̄, and how the quantum field emerges; d) an observational consequence of the new quantum field theory: a mass-dependent refraction index of vacuum. I will conclude with the research lines that will follow in the immediate future.