A Tale of Two Frames: a relativistic gedankenexperiment

S.T. Ali, Jean-Pierre Antoine, Jean‐Pierre Gazeau

Hiroaki Terashima, Masahito Ueda

We formulate the Einstein-Podolsky-Rosen (EPR) gedankenexperiment within the framework of relativistic quantum theory to analyze a situation in which measurements are performed by moving observers. We point out that under certain conditions the perfect anti-correlation of an EPR pair of spins in the same direction deteriorates in the moving observers' frame due to the Wigner rotation, and show that the degree of the violation of Bell's inequality prima facie decreases with increasing velocity of the observers if the directions of the measurement are fixed. However, this does not imply a breakdown of non-local correlation since the perfect anti-correlation is maintained in appropriately chosen different directions. When considering moving frames we must take account of this relativistic effect on the EPR correlation and on the violation of Bell's inequality for quantum communication.

G. C. Ghirardi

Shan Gao

It is shown that the combination of a unitary quantum theory and special relativity may lead to a contradiction when considering the statistics of certain measurement results in different Lorentz frames in a Gedankenexperiment. This result seems to imply that either unitary quantum theories are wrong or if a unitary quantum theory is right then there must exist a preferred Lorentz frame.

Douglas Snyder

Bennett et al.'s original article on quantum teleportation did not address explicitly synchronizing the orientation of the local spatial reference frames from and to which teleportaton occurs where the state teleported is spin 1/2 along the z axis. They wrote that only two bits of information need to be conveyed classically where the state to be teleported concerns spin 1/2 along the z axis. That only two bits of information need to be classically conveyed could imply that such synchronization is not needed for it would require more classically conveyed information. A gedankenexperiment is presented regarding the orientation of the local spatial reference frames exploring whether such synchronization is not needed even though it was apparently assumed by Bennett et al. that it was required. It is often assumed that there is an absolute, as opposed to a relative, orientation of objects in space. This assumption should be open to empirical test, especially in view of evidence in psychology that the orientation of objects in space is not absolute.