Group Theoretical Derivation of Consistent Massless Particle Theories

Current theories of massless free particle assume unitary space inversion and anti-unitary time reversal operators. In so doing robust classes possible are discarded. the present work systems derived through a strictly deductive development from principle relativistic invariance, that kind or operator is ruled out only if it causes inconsistencies. As results, new consistent for isolated explicitly determined. On other hand, approach determines definite constraints implied by invariance principle; they were ignored some past investigations that, as consequence, turn to be not with principle. Also problem localizability reconsidered within theoretical framework, obtaining generalization deeper detailing previous results.