Who was the first person to describe Relational Quantum mechanics and has worked in Italy, the United States, and France?
Relational quantum mechanics: Relational quantum mechanics (RQM) is an interpretation of quantum mechanics which treats the state of a quantum system as being observer-dependent, that is, the state "is" the relation between the observer and the system. Relational quantum mechanics:  This interpretation was first delineated by Carlo Rovelli in a 1994 preprint, and has since been expanded upon by a number of theorists. Carlo Rovelli: Carlo Rovelli (born 3 May 1956) is an Italian theoretical physicist and writer who has worked in Italy, the United States and since 2000, in France.
Carlo Rovelli