Starobinsky-Like Inflation in Dilaton-Brane Cosmology
Abstract
We discuss how Starobinsky-like inflation may emerge from dilaton dynamics in brane cosmology scenarios based on string theory, in which our universe is represented as a three-brane. The effective potential may acquire a constant term from a density of effectively point-like non-pertubative defects on the brane. Higher-genus corrections generate corrections to the effective potential that are exponentially damped at large field values, as in the Starobinsky model, but at a faster rate, leading to a smaller prediction for the tensor-to scalar perturbation ratio r. This may be compensated partially by logarithmic deformations on the world-sheet due to recoil of the defects due to scattering by string matter on the brane, which tend to enhance the tensor-to-scalar ratio.
Cite
@article{arxiv.1402.5075,
title = {Starobinsky-Like Inflation in Dilaton-Brane Cosmology},
author = {John Ellis and Nick E. Mavromatos and Dimitri V. Nanopoulos},
journal= {arXiv preprint arXiv:1402.5075},
year = {2015}
}
Comments
6 pages, 1 figure, Note Added to discuss BICEP2 data in connection with the present class of stringy inflation models. References added. No effect on conclusions other than the statement that D-particle fluctuations may provide independent (from dilaton) sources of tensor perturbations that enhance the tensor-to-scalar ratio in agreement with BICEP2 data. Version to appear in Phys. Lett. B