To. Decarvalho et al., FLUCTUATIONS IN QUANTUM EXPECTATION VALUES FOR CHAOTIC SYSTEMS WITH BROKEN TIME-REVERSAL SYMMETRY, Journal of physics. A, mathematical and general, 31(26), 1998, pp. 5631-5640
The semiclassical analysis of Eckhardt et al for the variance of quant
um expectation values in classically chaotic systems is extended to ob
tain the transitional form as time-reversal symmetry is gradually brok
en. Numerical results for a family of perturbed cat maps confirm this
analysis, including the halving of the variance as time-reversal symme
try is fully broken.