Lorenzo Maccone is an associate professor at the University of Pavia, Italy. He is a theoretical physicist, mainly interested in the

study of fundamental aspects and of practical applications of Quantum Mechanics. His research activities have been chiefly devoted to

quantum optics, quantum theory of measurement, and quantum information theory.

Closed timelike curves (CTCs) are trajectories in spacetime that
effectively travel backwards in time: a test particle following a CTC
can in principle interact with its former self in the past. CTCs appear
in many solutions of Einstein's field equations and any future quantum
version of general relativity will have to reconcile them with the
requirements of quantum mechanics and quantum field theory. A widely
accepted quantum theory of CTCs was proposed by Deutsch. Here we analyze an alternative quantum formulation of CTCs based on quantum
teleportation and post-selection and show that it is physically
inequivalent to Deutsch's. We show how our theory deals with the
time-travel paradoxes. The predictions/retrodictions of our theory are
experimentally testable: we report the results of an experiment
demonstrating our theory's resolution of the `grandfather paradox.