title: Closed timelike curves via postselection: theory and experimental test of consistency.
abstract: Closed timelike curves (CTCs) are trajectories in spacetime that effectively travel backwards in time: a test particle following a CTC can interact with its former self in the past. A widely accepted quantum theory of CTCs was proposed by Deutsch. Here we analyze an alternative quantum formulation of CTCs based on teleportation and postselection, and show that it is inequivalent to Deutsch's. The predictions or retrodictions of our theory can be simulated experimentally: we report the results of an experiment illustrating how in our particular theory the "grandfather paradox" is resolved.
authors.affiliation: xQIT, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA.
authors.forename: Seth
authors.initials: S
authors.lastname: Lloyd
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Maccone
authors.forename: Raul
authors.initials: R
authors.lastname: Garcia-Patron
authors.forename: Vittorio
authors.initials: V
authors.lastname: Giovannetti
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Shikano
authors.forename: Stefano
authors.initials: S
authors.lastname: Pirandola
authors.forename: Lee A
authors.initials: LA
authors.lastname: Rozema
authors.forename: Ardavan
authors.initials: A
authors.lastname: Darabi
authors.forename: Yasaman
authors.initials: Y
authors.lastname: Soudagar
authors.forename: Lynden K
authors.initials: LK
authors.lastname: Shalm
authors.forename: Aephraim M
authors.initials: AM
authors.lastname: Steinberg