My thoughts on what the Hubble tension really is, based on George Efstathiou’s “To H0 or not to H0?“, arXiv:2103.08723.
This week I cover a proposal to confirm the possible Dirac nature of neutrinos exploiting a subtle correlation between cosmological and terrestrial measurements, how to determine the sound horizon and H0 from BAO independently of the details of recombination, and a possible interpretation of the recent detection of the stochastic gravitational wave background at nHz frequencies by NANOGrav as being due to cosmic strings. Enjoy and have a nice weekend!
For a change, no H0 tension in this week’s entry (although I briefly touch on a new H0 measurement in paper 1)! This week I cover a new way to measure cosmological distances, a new dark matter candidate from an alternative to black holes, and the first calculation of how the neutrino Casimir force depends on the Dirac vs Majorana nature of neutrinos. Enjoy, and stay at home!
