Misc,
Dark Energy from Large Extra Dimensions
(December 2004)
Abstract
We explore in detail a model by Albrecht, Burgess, Ravndal and Skordis, where
a radion field from two compact extra dimensions gives rise to quintessence in
our 4-dimensional world. We show that the model can give rise to other types of
cosmologies as well, some more akin to k-essence and also variants of phantom
dark energy. In our realization of the scenario the radius stabilization arises
not from the Casimir potential, but from quantum corrections to the effective
4D Ricci-scalar. We show that the new stabilation scheme can be implemented in
a converging perturbation expansion for the effective 4D action without fine
tuning. We then show that various constraints nearly determine the expansion
parameters, and give an example of a quintessence-type cosmology consistent
with observations. We show that the upcoming SNAP-experiment would easily
distinguish the present model from a constant Lambda model with an equal amount
of dark energy, but that the SNAP-data alone will not be able distinguish it
from a Lambda model with about 5% less dark energy
