Resolving the Hubble Tension via SV0 Early Dark Energy and Modified Sound Horizon

Abstract:The Hubble Tension—the 4-5σ discrepancy between the local measurement of the Hubble constant H0 (e.g., SH0ES) and the value inferred from the Cosmic Microwave Background (CMB) assuming ΛCDM—remains one of the most pressing problems in modern cosmology. In this paper (Paper XXX of the SV0 series), we present a natural resolution of this tension within the Signed-Volume (SV0) framework. We demonstrate that the SV0 exchange law dynamically generates a small fraction of Early Dark Energy (EDE) prior to the recombination epoch. This EDE component increases the Hubble expansion rate H(z) at z ≈ 1100, thereby reducing the comoving sound horizon rd. Because the angular size of the sound horizon θs is tightly constrained by Planck, a smaller rd requires a larger H0 to maintain the observed angular scale. We show that the SV0 model naturally predicts H0 ≈ 72-73 km/s/Mpc, resolving the tension while preserving the successful predictions of Big Bang Nucleosynthesis (BBN) and the late-time cosmic acceleration. Keywords:Hubble Tension; Early Dark Energy; SV0 Theory; Sound Horizon; Cosmology; BBN; Cosmic Microwave Background.