Numerical Black Hole Interiors and String Cosmology Initial Conditions

TL;DR

This paper investigates the initial conditions of string cosmology using numerical simulations of gravitational collapse in the gravity-dilaton system, proposing that the pre-big bang scenario is as generic as gravitational collapse.

Contribution

It introduces a numerical analysis of the gravity-dilaton system in spherical symmetry to explore initial conditions in string cosmology, linking gravitational collapse to pre-big bang scenarios.

Findings

Numerical results support the idea that pre-big bang conditions are as generic as gravitational collapse.

The study demonstrates the transition from weak to strong field regimes in the model.

Insights into the initial state of the universe in string cosmology are provided.

Abstract

Recent work has proposed the principle of `asymptotic past triviality' to characterize the initial state in the pre-big bang scenario of string cosmology, that it is a generic perturbative solution of the low-energy effective action. Among the more generic sets of solutions which is simple enough to investigate thoroughly, yet complex enough to exhibit interesting behavior, is the gravity-dilaton system in spherical symmetry. Since, in the Einstein frame, this system reduces to a massless minimally coupled scalar, which has been target of a large body of previous investigation, we will draw on this and interpret it in the cosmological context. Since this scenario necessarily involves the transition from weak field initial data into the strong field regime, gravitational collapse, we have made numerical computations to answer some of the questions raised on the road to the proposal that `the pre-big bang is as generic as gravitational collapse'.