1206.5115 (Tobias Fritz)

Bell's Theorem without Free Will    [PDF]

Tobias Fritz

Bell's Theorem witnesses that the predictions of quantum theory cannot be reproduced by theories of local hidden variables in which observers have free will. In this context, free will means that the agents conducting measurements can choose between different measurement settings in each run of the experiment, and this choice is random and independent of the source. Here we show how to replace the need for having different measurement settings for each party by the introduction of several independent sources. Working out an idea of Branciard, Rosset, Gisin and Pironio, we obtain new versions of Bell's Theorem which discard those local hidden variable theories in which the sources are independent. Since each party has only one measurement setting in these scenarios, there is no choice required and the consideration of free will becomes obsolete. This adds conceptual clarity to Bell's Theorem and eliminates the philosophical burden associated to the concept of free will. Moreover, it is more general than the standard framework: we describe examples of quantum nonlocality which were previously unspeakable.

View original: http://arxiv.org/abs/1206.5115