Anisotropic Null String Cosmologies

TL;DR

This paper investigates string behavior in anisotropic cosmological backgrounds, deriving analytical solutions for tensionless strings and exploring their cosmological implications.

Contribution

It introduces a perturbative method to solve string equations in anisotropic backgrounds, providing exact solutions up to first order and analyzing their cosmological significance.

Findings

Exact zeroth and first order solutions for string propagation

Analytical expressions for tensionless string behavior

Discussion of cosmological implications of anisotropic string dynamics

Abstract

We study string propagation in an anisotropic, cosmological background. We solve the equations of motion and the constraints by performing a perturbative expansion of the string coordinates in powers of c^2, the world-sheet speed of light. To zeroth order the string is approximated by a tensionless string (since c is proportional to the string tension T). We obtain exact, analytical expressions for the zeroth and the first order solutions and we discuss some cosmological implications.