H_0-tension in the classical limit of Big Bang quantum cosmology

ΛCDM is challenged by observational tensions between late- and early-time cosmology, most dramatically in the Hubble constant H_0. ΛCDM hereby falls short as an effective infra-red (IR) limit of quantum cosmology. Consistency with general relativity in an effective dark energy Λ=α_pΛ_0∼ H^2/c^2 obtains from an IR-coupling α_p∼ħ to the bare cosmological constant Λ_0∼ 1/ħ, where ħ is the Planck constant. A path integral formulation with gauged total phase identifies Λ with the trace of the Schouten tensor J. It predicts the scaling H_0≃√(6/5)H_0^Λ CDM inferred from the BAO, while preserving the age of the Universe. With no free parameters, this first principle model predicts a 9% departure in H_0 between the Local Distance Ladder and the ΛCDM Planck measurements with no tension between late and early times. In galaxies, the same IR coupling predicts a sharp transition to anomalous rotation curves below the de Sitter acceleration a_dS=cH, where c is the velocity of light. Excluded by galaxy models in ΛCDM, it points to ultra-light dark matter of mass m_D≲ 3× 10^-21eV consistent with m_D≳ 10^-22eV of wave-like ψCDM.