2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/101911We present quantitative and qualitative arguments in favor of the claim that, within the present cosmological epoch, the U(1)$_Y$ factor in the Standard Model is an effective manifestation of SU(2) pure gauge dynamics of Yang-Mills scale $Λ\sim 10^{-4}$ eV. Results for the pressure and the energy density in the deconfining phase of this theory, obtained in a nonperturbative and analytical way, support this connection in view of large-angle features inherent in the map of the CMB temperature fluctuations and temperature-polarization cross correlations.13 pages, 9 figures, talk given at 29th Johns Hopkins workshop in Theoretical Physics, Budapest 1-3 August 2005; v3: consequences of a modification of the evolution equation for the coupling implementedHigh Energy Physics - Phenomenologytext