Looking back in time beyond the big bang

Abstract

String theory can (in principle) describe gravity at all curvature scales, and can be applied to cosmology to look back in time beyond the Planck epoch. The duality symmetries of string theory suggest a cosmological picture in which the imprint of a primordial, pre-big bang phase could still be accessible to present observations. The predictive power of such a scenario relies, however, on our ability to connect in a smooth way the pre-big bang to the present cosmological regime. Classical radiation back reaction seems to play a key role to this purpose, by isotropizing and turning into a final expansion any state of anisotropic contraction possibly emerging from the pre-big bang at the string scale.

11 pages, Latex, four figures included using epsfig. Essay written for the 1999 Awards of the Gravity Research Foundation (Wellesley Hills, Ma, 02481-0004), and selected for Honorable Mention. To appear in Mod. Phys. Lett. A

References in corpus (3)

• The Energy-Momentum Tensor for Cosmological Perturbations
• Graceful Exit and Energy Conditions in String Cosmology
• Loop corrections and graceful exit in string cosmology

Cited by in corpus (7)

• The Pre-Big Bang Scenario in String Cosmology
• Gravitational waves in non-singular string cosmologies
• From the string vacuum to FLRW or de Sitter via ${\alpha }^{\prime }$ corrections
• Low-energy graceful exit in anisotropic string cosmology backgrounds
• From pre- to post-big bang: an (almost) self-dual cosmological history
• Sufficient conditions for curvature invariants to avoid divergencies in Hyperextended Scalar Tensor theory for Bianchi models
• Rotational inhomogeneities from pre-big bang?