Entropy and Quantum States of Tachyon Supertube
  We quantize the deformed modes of a single supertube solution with regular profile of circular cross section on the unstable non-BPS D3-branes by using the Minahan-Zwiebach tachyon action. The result is used to count the microstates in an ensemble of supertube with fixed macroscopic quantities of charges $Q_{D0}$, $Q_{F1}$ and angular momentum $J$. We show that the entropy of the system is proportional to $\sqrt{Q_{D0}Q_{F1} - J}$, which is consistent with that calculated by the DBI action. Therefore, besides the well known properties that the kink solution (and its fluctuation) of tachyon DBI action corresponds with the brane solution (and its fluctuation) of DBI action, our result establishes a property that the entropy of the tachyon supertube in tachyonic DBI action corresponds with that of the supertube in DBI action. 
Wung-Hong Huang