Hubble Hullabaloo and String Cosmology
  The discrepancy in measurements of the Hubble constant indicates new physics
in dark energy, dark matter, or both. Drawing inspiration from string theory,
we explore possible solutions to overcome the $H_0$ problem. We investigate the
interplay between the cosmological determination of $\Delta N_{\rm eff}{}$ and
$Z'{}$ searches at the LHC Run3.
