The D1/D5 System And Singular CFT

TL;DR

This paper investigates the conformal field theory of the D1/D5 brane system on T^4 or K3, revealing a continuum spectrum above a gap that causes theoretical inconsistencies and clarifies discrepancies in spectrum calculations.

Contribution

It provides a detailed analysis of the D1/D5 system's CFT, identifying the origin of continuum spectra and associated pathologies in the moduli space.

Findings

Spectrum exhibits a continuum above a gap when branes can separate

Continuum spectrum explains discrepancies in chiral field calculations

Pathologies in the CFT are linked to the moduli space structure

Abstract

We study the conformal field theory of the D1/D5 system compactified on X (X is T^4 or K3). It is described by a sigma model whose target space is the moduli space of instantons on X. For values of the parameters where the branes can separate, the spectrum of dimensions in the conformal field theory exhibits a continuum above a gap. This continuum leads to a pathology of the conformal field theory, which explains a variety of problems in various systems. In particular, we explain the apparent discrepancy between different methods of finding the spectrum of chiral fields at certain points in the moduli space of the system.