Information Entropy in Cosmology
Abstract
The effective evolution of an inhomogeneous cosmological model may be described in terms of spatially averaged variables. We point out that in this context, quite naturally, a measure arises which is identical to a fluid model of the KullbackLeibler relative information entropy, expressing the distinguishability of the local inhomogeneous mass density field from its spatial average on arbitrary compact domains. We discuss the time evolution of “effective information” and explore some implications. We conjecture that the information content of the Universe—measured by relative information entropy of a cosmological model containing dust matter—is increasing.
 Publication:

Physical Review Letters
 Pub Date:
 April 2004
 DOI:
 10.1103/PhysRevLett.92.141302
 arXiv:
 arXiv:grqc/0402076
 Bibcode:
 2004PhRvL..92n1302H
 Keywords:

 98.80.k;
 04.40.b;
 89.70.+c;
 Cosmology;
 Selfgravitating systems;
 continuous media and classical fields in curved spacetime;
 Information theory and communication theory;
 Astrophysics;
 General Relativity and Quantum Cosmology
 EPrint:
 LateX, PRLstyle, 4 pages