Issue
EPL
Volume 86, Number 1, April 2009
Article Number 18004
Number of page(s) 6
Section Interdisciplinary Physics and Related Areas of Science and Technology
DOI http://dx.doi.org/10.1209/0295-5075/86/18004
Published online 21 April 2009
EPL, 86 (2009) 18004
DOI: 10.1209/0295-5075/86/18004

Fidelity measure and conservation of information in general probabilistic theories

C. Zander1 and A. R. Plastino1, 2, 3

1   Department of Physics, University of Pretoria - 0002 Pretoria, South Africa
2   National University La Plata, UNLP-CREG-CONICET - C.C. 727, 1900 La Plata, Argentina
3   Instituto Carlos I de Física Teórica y Computacional, University of Granada - Granada, Spain, EU

arplastino@maple.up.ac.za

received 12 January 2009; accepted in final form 16 March 2009; published April 2009
published online 21 April 2009

Abstract
We investigate the main features of a measure of fidelity between states in a general family of probabilistic theories admitting classical probability theory and standard quantum theory as particular instances. We apply the aforementioned measure to investigate information-theoretical features of these theories related to the conservation of information during the evolution of closed physical systems. In particular, we derive a generalization of a fundamental result in quantum theory relevant for the measurement problem: Zurek's recent extension of the no-cloning theorem.

PACS
89.70.-a - Information and communication theory.
05.90.+m - Other topics in statistical physics, thermodynamics, and nonlinear dynamical systems.
03.65.Ta - Foundations of quantum mechanics; measurement theory.

© EPLA 2009