Uniqueness of Tachyonic Solitons
  It has been conjectured that condensation of tachyons on a bosonic D-brane gives rise to vacuum / soliton solutions which are independent of the initial magnetic field on the D-brane. We present evidence for this conjecture using results from two dimensional conformal field theory. In particular we identify a continuous path in the configuration space of open string fields which interpolates between D-brane configurations with two different quantized magnetic flux. 
Ashoke Sen