Acc. Coolen et D. Sherrington, ORDER-PARAMETER FLOW IN THE FULLY CONNECTED HOPFIELD MODEL NEAR SATURATION, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 49(3), 1994, pp. 1921-1934
We present an exact dynamical theory, valid on finite time scales, to
describe the fully connected Hopfield model near saturation in terms o
f deterministic flow equations for order parameters. Two transparent a
ssumptions allow us to perform a replica calculation of the distributi
on of intrinsic-noise components of the alignment fields. Numerical si
mulations support our assumptions and indicate that our equations desc
ribe the shape of the intrinsic-noise distribution and the macroscopic
dynamics correctly in the region where replica symmetry is stable. In
equilibrium our theory reproduces the saddle-point equations obtained
in the thermodynamic analysis by Amit, Gutfreund, and Sompolinsky [Ph
ys. Rev. A 32, 1007 (1985); Phys. Rev. Lett. 55, 1530 (1985)], the onl
y difference being the absence in the present formalism of negative en
tropies at low temperatures.