Open String Fields as Matrices
  We show that the action expanded around Erler-Maccaferri's N D-brane solution describes the N+1 D-brane system where one D-brane disappears due to tachyon condensation. String fields on multi-branes can be regarded as block matrices of a string field on a single D-brane in the same way as matrix theories. 
Isao Kishimoto, Toru Masuda, Tomohiko Takahashi and Shoko Takemoto
hep-th