New physics in light of the H 0 tension: An alternative view

The strong discrepancy between local and early-time (inverse distance ladder) estimates of the Hubble constant ${H}_{0}$ could be pointing towards new physics beyond the concordance $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ model. Several attempts to address this tension through new physics rely on extended cosmological models, featuring extra free parameters beyond the six $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ parameters. However, marginalizing over additional parameters has the effect of broadening the uncertainties on the inferred parameters (including ${H}_{0}$), and it is often the case that within these models the ${H}_{0}$ tension is addressed due to larger uncertainties rather than a genuine…

• KF
  Kavli Foundation
• IN
  Isaac Newton Trust
• HC
  Homerton College, University of Cambridge