FM 96-1

Federico Bonetto, Giovanni Gallavotti

Reversibility, coarse graining and the chaoticity principle

Abstract: We describe a way of interpreting the chaotic
principle of ref. [GC1] more extensively than it was meant
in the original works. Mathematically the analysis is
based on the dynamical notions of Axiom A and Axiom B and
on the notion of Axiom C, that we introduce arguing that
it is suggested by the results of an experiment
(ref. [BGG]) on chaotic motions. Physically we interpret a
breakdown of the Anosov property of a time reversible
attractor (replaced, as a control parameter changes, by an
Axiom A property) as a spontaneous breakdown of the time
reversal symmetry: the relation between time reversal and
the symmetry that remains after the breakdown is analogous
to the breakdown of $T$-invariance while $TCP$ still
holds.

Keywords: Strange attractors, Chaoticity principle, Time
reversal, TCP


Fisica, Universita' di Roma La Sapienza,
P.le Moro 2, 00185, Roma, Italia.
e-mail bonetto@ipparco.roma1.infn.it, 
       giovanni@ipparco.roma1.infn.it
tel. 6-49914370, fax 6-4957697