Dynamic density functional description of fluids.
Umberto Marini Bettolo Marconi
Abstract
We present a new time-dependent Density Functional
approach to study the relaxational
dynamics of an assembly of interacting particles subject to thermal noise.
Starting from the Langevin stochastic equations of motion for
the velocities of the particles we are able by means of an
approximated closure to derive a self-consistent deterministic equation
for the temporal evolution of the average particle density.
The closure is equivalent to assuming that the equal-time two-point
correlation function out of equilibrium has the same properties as
its equilibrium version.
The changes in time of the density depend on the functional derivatives
of the grand canonical free energy functional $F[rho]$ of the system.
In order to assess the validity of our approach we performed a comparison
between the Langevin dynamics and the dynamic density functional method
for a one-dimensional hard-rod system in three relevant cases and
found remarkable agreement. In addition, we consider the case where one
is forced to use an approximate form of $F[rho]$.
Elenco dei partecipanti al convegno di Bari.