Participatory horizons and the cosmic dipole anomaly II: a cross-survey analysis

The dipole anisotropy in extragalactic source number counts exceeds the kinematic prediction from the CMB rest frame by a factor of two to three across multiple wavebands, with no settled explanation from local structure or survey systematics. The participatory-horizon programme proposes that the observer's causal diamond acts as an information aperture whose dipolar (L=1) component couples the source-count monopole into the observed dipole along the velocity axis, producing a universal additive excess D_ = A. In an earlier companion paper, we anchored this framework to the CatWISE2020 quasar catalogue (A = 5. 3 1. 3, 4. 0) and advanced two cross-survey predictions: a parameter-free G-ratio test and a transverse-null diagnostic. Here we test both by applying the same -projected decomposition to three independent surveys spanning five orders of magnitude in observing frequency: CatWISE (3. 4\, m, mid-infrared quasars), RACS-low (887\, MHz, radio galaxies), and NVSS (1. 4\, GHz, radio galaxies). For RACS and NVSS we project the Bayesian Poisson dipole posteriors (48\, 000+ MCMC samples each) onto the CMB velocity axis. The parameter-free G-ratio between CatWISE and RACS is consistent with the prediction at 0. 5. As a supporting diagnostic, D_ is stable across the three surveys (coefficient of variation 13\%) while the transverse component D_ is more than twice as variable (CV 30\%), consistent with a -aligned excess and survey-dependent off-axis contamination. Two additional catalogues were tested as stress tests: Quaia is excluded on systematic grounds (A 38, direction unstable under Galactic latitude cuts), and WISESuperCOSMOS is excluded because local large-scale structure dominates at z₌₄₃ 0. 2. These results provisionally support a universal, population-independent dipole excess of A 5--7 across mid-infrared and radio source populations, and motivate further empirical tests of the hypothesis.