Role of dynamical early dark energy in Hubble tension through warm inflation

Abstract

The role of dissipation from the thermal bath of minimal warm inflation (MWI)is examined with the Cosmic Microwave Background (CMB) to assess its ability to mimic a dynamical dark energy component. An increase in the dissipation strength modifies temperature anisotropies and shifts the phase and peak structure of the CMB TT angular power spectrum in a manner analogous to evolving dark energy. Bayesian parameter estimation for cosmological parameters of MWI using Markov Chain Monte Carlo analysis with Planck18 + BICEP/Keck 2018 + sn.pantheon + SH0ES likelihoods reveals deviations from standard $\Lambda$CDM constraints, accompanied by an enhancement in the matter power spectrum that signals possible physics beyond the conventional model. Notably, the present day Hubble parameter increases with dissipation strength, indicating that minimal warm inflation can naturally generate a dynamical early dark energy like behavior capable of alleviating the Hubble tension. Within this unified framework, early and late time estimates of $H_0$ can be reconciled. Further, the time varying dark energy equation of state consistent with recent DESI DR2 indication favours a quantum gravity phase preceding the inflationary epoch.