Electronic Journal of Differential Equations,
Conference 04 (2000), pp. 215-229.

Title:  Consistent histories: Description of a world with increasing entropy

Author: C. H. Woo (Univ. of Maryland, College Park, MD, USA)
 
Abstract: 
A distinction is made between two kinds of consistent histories: 
(1) robust histories consistent by virtue of decoherence, and 
(2) verifiable histories consistent through the existence of accessible 
records. It is events in verifiable histories which describe amplified 
quantum fluctuations. If the consistent-histories formalism is to 
improve on the Copenhagen interpretation by providing a self-contained 
quantum representation of the quasi-classical world, the appropriate 
quantum state must track closely all macroscopic phenomena, and the 
von Neumann entropy of that quantum state ought to change in the same 
direction as the statistical entropy of the macro-world. Since the 
von Neumann entropy tends to decrease under successive branchings, 
the evolution of an entropy-increasing quasi-classical world is not 
described by a process of branchings only: mergings of previously 
separate histories must also occur. As a consequence, the number 
of possible quasi-classical worlds does not have to grow indefinitely 
as in the many-world picture.

Published July 12, 2000.
Math Subject Classifications: 81P05, 81P10, 81P15.
Key Words: Consistent histories; entropy; second law.