2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/121431A general local approach for the definition of velocities and especially phase velocities for waves recently proposed for one-dimensional waves is generalized for 2 and 3 dimensional scalar wave. A geometrically consistent generalization has been found for the local wave velocities of order zero and one.5 pagesMathematical Physicstext