My thoughts on what the Hubble tension really is, based on George Efstathiou’s “To H0 or not to H0?“, arXiv:2103.08723.
After disappearing for a week, this week I cover three papers discussing why reducing the sound horizon is necessary but not sufficient to solve the Hubble tension, how to probe gravitational waves using astrometry, and whether unparticles might have something to do with dark energy. As of this week I’ve also decided to start including plots from the respective papers, where necessary, in my summaries, as a good plot is worth a thousand words. Enjoy!
End-of-the-week synopses looking at the possibility of directly detecting dark energy fluctuations using anisotropies in gravitational wave luminosity distances, constraints on baryonic effects from the DES Y1 data, and revisiting constraints on the CMB temperature and whether the latter might have some bearings on the H0 tension. A heads-up that this will be the last entry for the next 5 weeks, as I’m going on holiday. Enjoy, and see you again here in mid-September!
