  The non-equilibrium self-consistent generalized Langevin equation theory of
irreversible processes in liquids is extended to describe the positional and
orientational thermal fluctuations of the instantaneous local concentration
profile $n(\mathbf{r},\Omega,t)$ of a suddenly-quenched colloidal liquid of
particles interacting through non spherically-symmetric pairwise interactions,
whose mean value $\overline{n}(\mathbf{r},\Omega,t)$ is constrained to remain
uniform and isotropic, $\overline{n}(\mathbf{r},\Omega,t)=\overline{n}(t)$.
Such self-consistent theory is cast in terms of the time-evolution equation of
the covariance $\sigma(t)=\overline{\delta n_{lm}(\mathbf{k};t) \delta
n^{\dagger}_{lm}(\mathbf{k};t)}$ of the fluctuations $\delta
n_{lm}(\mathbf{k};t)=n_{lm}(\mathbf{k};t) -\overline{n_{lm}}(\mathbf{k};t)$ of
the spherical harmonics projections $n_{lm}(\mathbf{k};t)$ of the Fourier
transform of $n(\mathbf{r},\Omega,t)$. The resulting theory describes the
non-equilibrium evolution after a sudden temperature quench of both, the static
structure factor projections $S_{lm}(k,t)$ and the two-time correlation
function $F_{lm}(k,\tau;t)\equiv\overline{\delta n_{lm}(\mathbf{k},t)\delta
n_{lm}(\mathbf{k},t+\tau)}$, where $\tau$ is the correlation \emph{delay} time
and $t$ is the \emph{evolution} or \emph{waiting} time after the quench. As a
concrete and illustrative application we use the resulting self-consistent
equations to describe the irreversible processes of equilibration or aging of
the orientational degrees of freedom of a system of strongly interacting
classical dipoles with quenched positional disorder.
