Closed timelike curves via post-selection: theory and experimental demonstration

Abstract

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 of quantum field theory. A widely accepted quantum theory of CTCs was proposed by Deutsch. Here we explore an alternative quantum formulation of CTCs and show that it is physically inequivalent to Deutsch's. Because it is based on combining quantum teleportation with post-selection, the predictions/retrodictions of our theory are experimentally testable: we report the results of an experiment demonstrating our theory's resolution of the well-known `grandfather paradox.

5 pages, 4 figures

References in corpus (1)

• Can closed timelike curves or nonlinear quantum mechanics improve quantum state discrimination or help solve hard problems?

Cited by in corpus (9)

• The quantum mechanics of time travel through post-selected teleportation
• Quantum Data Compression of a Qubit Ensemble
• Experimental Simulation of Closed Timelike Curves
• The Evolving Block Universe and the Meshing Together of Times
• Andreev reflections and the quantum physics of black holes
• The information recovery problem
• Faster than light motion does not imply time travel
• Smooth Entropy Transfer of Quantum Gravity Information Processing
• Postselected quantum circuits