Spacelike boundaries from the c=1 Matrix Model

TL;DR

This paper explores classical solutions in two-dimensional noncritical string theory that produce spacetimes with spacelike boundaries, analyzing their causal structure and tachyon condensate behavior using the c=1 matrix model.

Contribution

It introduces a class of time-dependent solutions in the c=1 matrix model that generate geometries with spacelike boundaries, expanding understanding of noncritical string cosmologies.

Findings

Identified classical solutions with spacelike boundaries.

Mapped the causal structure of these spacetimes.

Analyzed the asymptotic tachyon condensate using the macroscopic loop transform.

Abstract

We find classical solutions of two dimensional noncritical string theory which give rise to geometries with spacelike boundaries, similar to spacetimes with cosmological event horizons. In the c=1 matrix model, these solutions have a representation as simple time dependent configurations. We obtain the causal structure of the resulting spacetimes. Using the macroscopic loop transform, we probe the form of the tachyon condensate in the asymptotic regions.