Brane Inflation and the Overshoot Problem
arXiv:0905.2412 · doi:10.1103/PhysRevD.80.023534
Abstract
We investigate recent claims that brane inflation solves the overshoot problem through a combination of microphysical restrictions on the phase space of initial conditions and the existence of the Dirac-Born-Infeld (DBI) attractor in regimes where the slow-roll attractor does not apply. Carrying out a comprehensive analysis of the parameter space allowed by the latest advances in brane inflation model-building, we find that these restrictions are insufficient to solve the overshoot problem. The vast majority of the phase space of initial conditions is still dominated by overshoot trajectories. We present an analytic proof that the brane-inflationary attractor must be close to the slow-roll limit, and update the predictions for observables such as non-Gaussianity, cosmic string tension and tensor modes.
14 pages, 3 figures, matches version published in PRD. Minor clarifications, references added
References in corpus (15)
- String Cosmology: A Review
- A Delicate Universe
- Small-Angle CMB Temperature Anisotropies Induced by Cosmic Strings
- Phenomenology of D-Brane Inflation with General Speed of Sound
- Stochastic Gravitational Wave Background from Light Cosmic Strings
- Holographic Systematics of D-brane Inflation
- Brane inflation and the WMAP data: a Bayesian analysis
- Inflation from Wrapped Branes
- Searching for Inflation in Simple String Theory Models: An Astrophysical Perspective
- New constraints on the observable inflaton potential from WMAP and SDSS
- Latest inflation model constraints from cosmic microwave background measurements
- Observing cosmic string loops with gravitational lensing surveys
- Cosmological constraints on general, single field inflation
- How Delicate is Brane-Antibrane Inflation?
- Fine-tuning criteria for inflation and the search for primordial gravitational waves