Elements of String Cosmology

TL;DR

This paper explores string cosmology, highlighting the importance of dilaton dynamics and duality, revealing how string effects modify traditional cosmological intuition and naturally produce a radiation-dominated era.

Contribution

It offers a new interpretation of string cosmology, emphasizing dilaton effects and duality, and connects non-critical string models to known black hole solutions.

Findings

Winding modes oppose expansion unless annihilated.

Radiation-dominated era emerges naturally in string cosmology.

Reinterpretation of 2D black hole solutions as cosmological models.

Abstract

Aspects of string cosmology for critical and non-critical strings are discussed emphasizing the necessity to account for the dilaton dynamics for a proper incorporation of ``large - small" duality. This drastically modifies the intuition one has with Einstein's gravity. For example winding modes, even though contribute to energy density, oppose expansion and if not annihilated will stop the expansion. Moreover we find that the radiation dominated era of the standard cosmology emerges quite naturally in string cosmology. Our analysis of non-critical string cosmology provides a reinterpretation of the (universal cover of the) recently studied two dimensional black hole solution as a conformal realization of cosmological solutions found previously by Mueller.