  The D2brane-anti-D2brane system is described in the framework of BFSS Matrix
model and noncommutative (NC) gauge theory. The physical spectrum of fields is
found by appropriate gauge fixing. The exact tachyon potential is computed in
terms of these variables and an exact description of tachyon condensation
provided. We exhibit multiple vortex production with increasing topological
charge and interpret this as gradual conversion of the brane-antibrane system
to $D0$ branes. The entire analysis is carried out using the known hamiltonian
of the Matrix model, which is equivalent to the hamiltonian of the NC gauge
theory. We identify the supersymmetric ground state of this hamiltonian with
the tachyonic vacuum; Sen's conjecture about the latter follows simply from
this identification. We also find two types of closed string excitations,
solitonic (a la Dijkgraaf, Verlinde and Verlinde) as well as perturbative,
around the tachyonic vacuum.
