“…The U (1, 3) = SU (1, 3)⊗ U (1) Group transformations which leave invariant the phase-space intervals under rotations, velocity and acceleration boosts, were found by Low [10] and can be simplified drastically when the velocity/acceleration boosts are taken to lie in the z-direction, leaving the transverse directions x, y, p x , p y intact ; i.e., the U (1, 1) = SU (1, 1) ⊗ U (1) subgroup transformations leave invariant the phasespace interval given by (in units ofh = c = 1)…”