Supersymmetric instantonic D1-branes in AdS$_5\times$S$^5$ background

TL;DR

This paper classifies and analyzes supersymmetric D1-brane instantons in the AdS$_5\times$S$^5$ background, identifying their configurations, supersymmetry properties, and relations to other instantons, revealing new BPS D1-brane solutions.

Contribution

It identifies and characterizes 1/2-BPS instantonic D1-brane configurations in AdS$_5\times$S$^5$, including their supersymmetry structures and relations to other instantons.

Findings

Spherical D1-instantons with radius of S$^5$ are 1/2-BPS.

Explicit 1/2-BPS D1-brane configurations are constructed.

Relations between D1-instantons and $(p,q)$ string instantons are discussed.

Abstract

According to the covariant open superstring description of 1/2-BPS D-branes in the AdS$_5\times$S$^5$ background, there are two kinds of purely instantonic D-branes. One is the well known D(-1)-brane or D-instanton, and another is the D1-brane spanning a two dimensional subspace inside S$^5$. We identify the actual 1/2-BPS instantonic D1-brane configurations and their supersymmetry structures. From the results, it is concluded that any spherical D1-instanton with the radius equal to that of S$^5$ is 1/2-BPS. After evaluating the 1/2-BPS D1-instanton action, we discuss the relation of D1-instanton with the $(p, q)$ string instanton. We also discuss the possible 1/2-BPS and 1/4-BPS multiple D1-instanton configurations.