2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/58833Using $\star$-product on Co-adjoint orbits (K-orbits) of the $\MD_4$- groups we obtain quantum half-planes, quantum hyperbolic cylinders, quantum hyperbolic paraboloids...via Fedosov deformation quantization. From this we have corresponding unitary representations of the $\MD_4$- groups. Particularly, for groups $\G_{4,2,3(ϕ)}; \G_{4,2,4}; \G_{4,3,4(ϕ)}$ and $ \G_{4,4,1} $, which are neither nilpotent nor exponential, we obtain the explicit formulas.AMS-LaTeX, 18 pagesQuantum AlgebraRepresentation Theorytext