1/4 BPS String Junctions and $N^3$ Problem in 6-dim (2,0) Superconformal Theories

TL;DR

This paper investigates 1/4 BPS objects in 6-dimensional (2,0) superconformal theories, revealing their role in accounting for the $N^3$ degrees of freedom through string junctions and anomaly matching.

Contribution

It identifies and counts 1/4 BPS objects in 6D (2,0) theories, linking their number to the anomaly constant and proposing they explain the $N^3$ degrees of freedom.

Findings

Number of 1/4 BPS objects matches one third of the anomaly constant $c_G$

These objects are composed of waves on selfdual strings and junctions

Suggests 1/4 BPS objects account for $N^3$ degrees of freedom in Coulomb phase

Abstract

We explore 1/4 BPS objects in the Coulomb phase of the ADE-type 6-dim (2,0) superconformal theories. By using the previous work on the junctions of strings in 5-dim gauge theories and 6-dim superconformal theories, we count the number of 1/4 BPS objects, which are made of waves on selfdual strings and junctions of selfdual strings and show that for all cases the number matches exactly one third of the anomaly constant $c_G=d_G h_G$ which is the product of dimension $d_G$ and dual Coxeter number $h_G$. This suggests the long sought after $N^3$ degrees of freedom are these 1/4 BPS objects at least in the Coulomb phase.