  The effective equation of state of normal matter is changed in theories where
the size of the compact space depends upon the local energy density. In
particular we show how the dilution of a fluid due to the expansion of the
universe can be compensated by an increase of the effective coupling of that
fluid to gravity in the presence of a potential which acts to reduce the size
of the compact space. We estimate how much cosmic acceleration can be obtained
in such a model and comment on the difficulties faced in finding an appropriate
potential.

High Energy Physics - Theory;Astrophysics;High Energy Physics - Phenomenology