Supersymmetric instantonic D1-branes in AdS(5) x S-5 background

Abstract

According to the covariant open superstring description of 1/2-BPS D-branes in the AdS(5)xS(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.