2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/75906Using the concept of a twisted trace density on a cyclic groupoid, a trace is constructed on a formal deformation quantization of a symplectic orbifold. An algebraic index theorem for orbifolds follows as a consequence of a local Riemann--Roch theorem for such densities. In the case of a reduced orbifold, this proves a conjecture by Fedosov, Schulze, and Tarkhanov. Finally, it is shown how the Kawasaki index theorem for elliptic operators on orbifolds follows from this algebraic index theorem.34 pages, and presentation improvedK-Theory and HomologyMathematical PhysicsSymplectic Geometrytext