Axion-Dilaton Destabilization and the Hubble Tension
  The discrepancy in measurements of the Hubble constant indicates new physics
in dark energy, dark matter, or both. Drawing inspiration from string theory,
where axions interact with the other moduli fields, including the dilaton, here
we demonstrate that the dynamics of an interacting dilaton and axion naturally
realizes the proposal of Early Dark Energy. In this setup, stabilization of the
the dilaton is in part due to the axion, and in the early universe the dilaton
contributes to dark energy. The combined axion-dilaton system is destabilized
when the Hubble constant falls below the mass of the axion, triggering a phase
of fast-roll evolution of the dilaton wherein its equation of state is $w=1$,
and the early dark energy redshifts away as $a^{-6}$.
