AdS3/AdS2 degression of massless particles

A bstract We study a 3d/2d dimensional degression which is Kaluza-Klein type mechanism in AdS 3 space foliated into 2 hypersurfaces. It shown that an massless particle of spin s = 1 , … ∞ degresses couple particles equal energies E . Note the spectra higher dimensions are always infinite. To formulate /AdS we consider branching rules for isometry algebra o(2,2) representations decomposed with respect to o(1,2). find given higher-spin representation lying on unitary bound (i.e. massless) decomposes two o(1,2) modules. In field-theoretical terms, this phenomenon demonstrated spin-2 and spin-3 free fields. The truncation finite spectrum can be seen by using particular mode expansions, (partial) diagonalizations, identities specific dimensions.