Renormalization Group Corrections to Λ CDM $\Lambda{\rm CDM}$ Model and Observational Consequences for H 0 $H_0$ Tension

Abstract

We explore the renormalization group-based extension of the $\Lambda \mathrm{CDM}$ model as a potential solution to the current cosmological tensions. In this approach, both the cosmological constant density and Newton's constant are allowed to vary with the energy scale, as a consequence of the remnant effects of massive quantum fields in the low-energy regime. The corresponding cosmological model is consistent with the principles of quantum field theory, based on the covariance of the vacuum effective action, and is characterized by a unique extra parameter $\nu$. Our analysis yields a best-fit value of $\nu =-(2.5\pm 1.3)\times {10}^{-4}$, placing the $\Lambda \mathrm{CDM}$ limit at the $2\sigma$ region of the $\nu$ posterior. This narrow range is consistent with data from CMB (Planck), BAO (DESI), and SN Ia (DES Y5). Our result also alleviates the $H_0$ tension and is consistent with the previously established constraints from large-scale structure. In these kind of models, there is a link between cosmology and particle physics. Our results point to possibility of a new physics, characterized by a mass spectrum lying below the Planck scale but above the values typically associated with Grand Unified Theories (GUTs).