Effective field origin of a length-scale step-varying Newton’s constant and the Hubble tension

Based on the observation that a sharp transition of the Newton’s constant [Formula: see text] at very late times/short distances would affect Cepheids and Type Ia Supernovae, solving the Hubble tension, in this work we argue that the emergence of an effective length-scale step-varying [Formula: see text] doing the job could be explained in the framework of the effective field theory of cosmological perturbations, due to the coarse graining of nonlinear short-wavelength modes. This would provide a new interpretation of the Hubble tension.