Tachyon Vacuum Solution in Open String Field Theory with Constant B   Field
  We show that Schnabl's tachyon vacuum solution is an exact solution of the equation of motion of Witten's open bosonic string field theory in the background of constant antisymmetric two-form field. The action computed at the vacuum solution is given by the Dirac-Born-Infeld factor multiplied to that without the antisymmetric tensor field. 
Akira Ishida (Sungkyunkwan U.), Chanju Kim (Ewha Womans U.), Yoonbai   Kim (Sungkyunkwan U.), O-Kab Kwon (Sungkyunkwan U.), ...