My thoughts on what the Hubble tension really is, based on George Efstathiou’s “To H0 or not to H0?“, arXiv:2103.08723.
After being “away” a few weeks where I used this blog as a conference diary (see TMCC2021 and A (Hubble) Tension Headache), the usual arXiv posts return, covering primordial black holes as (not) dark matter, difficulties in constructing working and realistic early dark energy models, and biases to parameter constraints from the effect of baryonic feedback on the gravitational lensing of the CMB. Enjoy the read!
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!
