Abstract
In quantum physics, the density operator completely describes the state. Instead, in classical physics the mean value of physical quantities is evaluated by means of a probability distribution. We study the possibility to describe pure quantum states and events with classical probability distributions and conditional probabilities and prove that the distributions have to be nonlinear functions of the density operator. Some examples are considered. Finally, we deal with the exponential complexity problem of quantum physics and introduce the concept of classical dimension for a quantum system.
- Received 19 December 2005
- Corrected 31 October 2006
DOI:https://doi.org/10.1103/PhysRevLett.97.180401
©2006 American Physical Society
Corrections
31 October 2006