English

Condition for macroscopic realism beyond the Leggett-Garg inequalities

Quantum Physics 2013-05-15 v3

Abstract

In 1985, Leggett and Garg put forward the concept of macroscopic realism (macrorealism) and, in analogy to Bell's theorem, derived a necessary condition in terms of inequalities, which are now known as the Leggett-Garg inequalities. In this paper, we discuss another necessary condition called no-signaling in time. It solely bases on comparing the probability distribution for a macrovariable at some time for the cases where previously a measurement has or has not been performed. Although the concept is analogous to the no-signaling condition in the case of Bell tests, it can be violated according to quantum mechanical predictions even in situations where no violation of Leggett-Garg inequalities is possible.

Keywords

Cite

@article{arxiv.1207.3666,
  title  = {Condition for macroscopic realism beyond the Leggett-Garg inequalities},
  author = {Johannes Kofler and Caslav Brukner},
  journal= {arXiv preprint arXiv:1207.3666},
  year   = {2013}
}

Comments

6 pages, 1 table, 1 figure, published version