The Physics of 2-d Stringy Spacetimes

TL;DR

This paper explores two-dimensional string-derived spacetimes, identifying black holes as the unique non-trivial solutions, analyzing their duality and thermodynamics, and extending the discussion to heterotic strings with considerations of exact solutions.

Contribution

It systematically classifies tachyon-free 2D string solutions, highlights the uniqueness of black holes, and investigates their thermodynamics and dualities, including heterotic string extensions.

Findings

Black hole solutions are the only non-trivial tachyon-free 2D string spacetimes.

Thermodynamics in 2D string spacetimes is complex due to dilaton redefinition issues.

Duality plays a significant role in understanding these solutions.

Abstract

We examine the two-dimensional spacetimes that emerge from string theory. We find all the solutions with no tachyons, and show that the only non-trivial solution is the black hole spacetime. We examine the role of duality in this picture. We then explore the thermodynamics of these solutions which is complicated by the fact that only in two spacetime dimensions is it impossible to redefine the dilaton field in terms of a canonical scalar field. Finally, we extend our analysis to the heterotic string, and briefly comment on exact, as opposed to perturbative, solutions.