Multibrane Solutions in Open String Field Theory
  We study properties of a class of solutions of open string field theory which depend on a single holomorphic function F(z). We show that the energy of these solutions is well defined and is given by integer multiples of a single D-brane tension. Potential anomalies are discussed in detail. Some of them can be avoided by imposing suitable regularity conditions on F(z), while the anomaly in the equation of motion seems to require an introduction of the so called phantom term. 
Masaki Murata, Martin Schnabl
hep-th