The Fredholm index conjecture for formal quantization of b-symplectic manifolds

Let $M$ be an integral $b$-symplectic manifold equipped with a Hamiltonian $T$-action with nonzero modular weight, and let $Q(M)$ denote its formal geometric quantization. Fredholm index conjecture. There exists a natural Fredholm operator on $M$ whose index gives $Q(M)$. This would provide an analytic index interpretation of the formal geometric quantization constructed in the paper; the source does not state that such an operator is known or identify a resolution of the conjecture.