Little String Origin of Surface Defects

TL;DR

This paper derives surface defects in 4d $ ext{N}=4$ SYM from the (2, 0) little string theory, connecting geometric, algebraic, and conformal field theory perspectives, and clarifying their classification and properties.

Contribution

It provides a geometric derivation of surface defects from little string theory and establishes their classification via nilpotent orbits and ADE Toda CFT, highlighting differences from the (2, 0) CFT limit.

Findings

Derived surface defects from little string theory using D-branes.

Connected defect classification to nilpotent orbits and ADE Toda CFT.

Identified differences between little string defects and (2, 0) CFT limit.

Abstract

We derive the codimension-two defects of 4d $\mathcal{N} = 4$ Super Yang-Mills (SYM) theory from the (2, 0) little string. The origin of the little string is type IIB theory compactified on an ADE singularity. The defects are D-branes wrapping the 2-cycles of the singularity. We use this construction to make contact with the description of SYM defects due to Gukov and Witten [arXiv:hep-th/0612073]. Furthermore, we derive from a geometric perspective the complete nilpotent orbit classification of codimension-two defects, and the connection to ADE-type Toda CFT. The only data needed to specify the defects is a set of weights of the algebra obeying certain constraints, which we give explicitly. We highlight the differences between the defect classification in the little string theory and its (2, 0) CFT limit.