Resolving the H0 tension with diffusion
Abstract
The tension between the value of the Hubble constant H0 determined from local supernovae data and the one inferred from the cosmic microwave background based on the cosmological model may indicate the need for new physics. Here, we show that this `Hubble tension' can be resolved in models involving an effective energy flux from the matter sector into dark energy resulting naturally from a combination of unimodular gravity and an energy diffusion process. The scheme is one where dark energy has the standard equation of state w=-1. This proposal provides an alternative phenomenological paradigm accounting for the observations, while offering a general framework to study diffusion effects coming from novel fundamental physical processes.
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