Cosmology on a cosmic ring
arXiv:1411.3328 · doi:10.1088/1475-7516/2015/03/050
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 non-linear 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.
28 pages, 4 figures; v2: matches version published in JCAP
References in corpus (25)
- Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
- Measurements of Omega and Lambda from 42 High-Redshift Supernovae
- 4D Gravity on a Brane in 5D Minkowski Space
- Resummation of Massive Gravity
- Massive Gravity
- Theoretical Aspects of Massive Gravity
- Brane cosmological evolution in a bulk with cosmological constant
- Cosmology on a Brane in Minkowski Bulk
- Strong Interactions and Stability in the DGP Model
- Gravity on a Brane in Infinite-Volume Extra Space
- Classical and Quantum Consistency of the DGP Model
- Degravitation of the Cosmological Constant and Graviton Width
- More on ghosts in DGP model
- Diluting Cosmological Constant In Infinite Volume Extra Dimensions
- DGP Specteroscopy
- Are there ghosts in the self-accelerating brane universe?
- Cascading Gravity and Degravitation
- Cosmological Constraints on DGP Braneworld Gravity with Brane Tension
- Generalization of the Geroch-Held-Penrose formalism to higher dimensions
- Charting the Landscape of Modified Gravity
- A New Perspective on DGP Gravity
- Self-gravity of Brane Worlds: A New Hierarchy Twist
- Interpreting spacetimes of any dimension using geodesic deviation
- Interpretation of the Weyl tensor
- The Universe as a Cosmic String