String Network and 1/4 BPS States in N=4 SU(n) Supersymmetric Yang-Mills   Theory
  We construct the classical configurations of BPS states with 1/4 unbroken supersymmetries in four-dimensional N=4 SU(n+1) supersymmetric Yang-Mills theory, and discuss that these configurations correspond to string networks connecting (n+1) D3-branes in Type IIB string theory. 
Teruhiko Kawano and Kazumi Okuyama (Univ. of Tokyo)