Quintessence axion dark energy and a solution to the hubble tension

Abstract

We present a model in which the question about a nature of the dark energy and the recently raised Hubble tension can be addressed at once. We consider the electroweak axion in the minimal supersymmetric standard model where the axion energy density is identified with the observed dark energy. Along with this, imposing a gauged Z10 symmetry makes it possible to have a gravitino dark matter whose mass amounts to ∼O(1) GeV. We find that the gravitino with mass ∼O(1) GeV can be a good candidate of a decaying dark matter of which decay after recombination can reconcile discrepancy in local measurements of the Hubble expansion rate H0 and that inferred from the cosmic microwave background observation.