  In a recent study Akarsu and Dereli (Gen. Relativ. Gravit. 45:1211, 2013)
discussed the dynamical reduction of a higher dimensional cosmological model
which is augmented by a kinematical constraint characterized by a single real
parameter, correlating and controlling the expansion of both the external
(physical) and internal spaces. In that paper explicit solutions were found
only for the case of three dimensional internal space ($n=3$). Here we derive a
general solution of the system using Lie group symmetry properties, in
parametric form for arbitrary number $n=1,2,3,\dots$ of internal dimensions. We
also investigate the dynamical reduction of the model as a function of cosmic
time $t$ for various values of $n$ and generate parametric plots to discuss
cosmologically relevant results.
