Brown-Kuchar Mechanism for Unstable D-Brane at Large Tachyon Regime

We study space-time filling unstable D-brane coupled to gravity. We find Hamiltonian for this D-brane and then we implement Brown-Kuchar formalism for this system. We calculate algebra of constraints of deparametrized theory and we show that for large $T$ the Poisson brackets between new constraints are zero. Then we define gauge invariant functions on phase space following deparametrization construction introduced in [9].