Sharp Endpoint \(L_p\) Estimates of Quantum Schrödinger Groups

In this article, we establish sharp endpoint \(L_p\) estimates of Schrödinger groups on general measure spaces which may not be equipped with good metrics but admit submarkovian semigroups satisfying purely algebraic assumptions. One of the key ingredients of our proof is to introduce and investigate a new noncommutative high-cancellation BMO space by constructing an abstract form of P-metric codifying some sort of underlying metric and position. This provides the first form of Schrödinger group theory on arbitrary von Neumann algebras and can be applied to many models, including Schrödinger groups associated with non-negative self-adjoint operators satisfying purely Gaussian upper bounds on doubling metric spaces, standard Schrödinger groups on quantum Euclidean spaces, matrix algebras, and group von Neumann algebras with finite dimensional cocycles.