Cosmology on a cosmic ring

Florian Niedermann, Robert Schneider

Keywords

No keywords

Abstract

We derive the modified Friedmann equations for a generalization of the Dvali-Gabadadze-Porrati (DGP) model in which the brane has one additional compact dimension. The main new feature is the emission of gravitational waves into the bulk. We study two classes of solutions: first, if the compact dimension is stabilized, the waves vanish and one exactly recovers DGP cosmology. However, a stabilization by means of physical matter is not possible for a tension-dominated brane, thus implying a late time modification of 4D cosmology different from DGP. Second, for a freely expanding compact direction, we find exact attractor solutions with zero 4D Hubble parameter despite the presence of a 4D cosmological constant. The model hence constitutes an explicit example of dynamical degravitation at the full nonlinear level. Without stabilization, however, there is no 4D regime and the model is ruled out observationally, as we demonstrate explicitly by comparing to supernova data.

Information

Published
2015 as article (english)
JCAP, 2015, 03 - page(s): 050
Type
theoretical work
Links
pdf
ads
dx.doi.org/10.1088/1…
Related to the research area(s):
A
e-Print
1411.3328

Technische Universitaet Muenchen
Exzellenzcluster Universe

Boltzmannstr. 2
D-85748 Garching

Tel. + 49 89 35831 - 7100
Fax + 49 89 3299 - 4002
info@universe-cluster.de