My thoughts on what the Hubble tension really is, based on George Efstathiou’s “To H0 or not to H0?“, arXiv:2103.08723.
Stochastic gravitational wave background
This week’s post is dedicated to dark energy in the context of (not solving) the Hubble tension, the possibility that the NANOGrav pulsar timing array may have detected non-tensorial gravitational wave polarizations, and the construction of a general covariant action for the so-called holographic dark energy model. Enjoy the read and have a nice weekend!
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!
