Effect of the deformation operator in the D1D5 CFT

TL;DR

This paper investigates how a specific deformation operator in the D1D5 conformal field theory affects states with different winding numbers, advancing understanding of black hole microstate dynamics and thermalization.

Contribution

It extends previous work by analyzing the full supersymmetric theory, including fermionic excitations, to understand the deformation operator's impact on various states.

Findings

Deformation links CFT copies with different winding numbers, creating new excited states.

Results generalize prior bosonic-only studies to include fermionic sectors.

Findings contribute to understanding thermalization and black hole formation in holography.

Abstract

The D1D5 CFT gives a holographic dual description of a near-extremal black hole in string theory. The interaction in this theory is given by a marginal deformation operator, which is composed of supercharges acting on a twist operator. The twist operator links together different copies of a free CFT. We study the effect of this deformation operator when it links together CFT copies with winding numbers M and N to produce a copy with winding M+N, populated with excitations of a particular form. We compute the effect of the deformation operator in the full supersymmetric theory, firstly on a Ramond-Ramond ground state and secondly on states with an initial bosonic or fermionic excitation. Our results generalize recent work which studied only the bosonic sector of the CFT. Our findings are a step towards understanding thermalization in the D1D5 CFT, which is related to black hole formation and evaporation in the bulk.