Field condensations and Noncritical String for c>1

TL;DR

This paper investigates the extension of 2d quantum gravity as a non-critical string theory for central charge c>1, revealing a new phase where boundary gauge fields condense, stabilizing the theory.

Contribution

It introduces a modified target-space action accounting for loop corrections, enabling a consistent extension of non-critical string theory beyond c=1.

Findings

Identification of a new phase with boundary gauge field condensation

Extension of non-critical string theory to c>1 without instability

Modified target-space action incorporating loop corrections

Abstract

Quantum theory of 2d gravity for $c>1$ is examined as a non-critical string theory by taking account of the loop-correction of open strings whose end points are on the 2d world surface of the closed string. This loop-correction leads to a conformal anomaly, and we obtain a modified target-space action which implies a new phase of the non-critical closed-string. In this phase, the dual field of the gauge field, which lives on the boundary, condenses and the theory can be extended to $c>1$ without any instability.