Two interesting new papers:
One indicates that new physics in the dark sector at the two scales, the eV scale and a ULA scale, close to those inherent in the Cold NEDE solution to the Hubble tension, could be required by eBOSS Lyman-alpha data https://arxiv.org/abs/2311.16377.
And one that constrains a corner of NEDE parameter space in more detail from the microphysics of the phase transition https://arxiv.org/abs/2311.16222, emphasizing the requirement of a fast phase transition.
The ESA Euclid experiment will map around a billion galaxies in the next six years and give us new insights into the properties of Dark Matter and Dark Energy. Today, Euclid released its first pictures: Euclid’s first images.
Not all approaches to the Hubble tension are equally good or bad. Some recent discussion seems to ignore the fact that early-time approaches like New Early Dark Energy also fit the CMB better than Lambda-CDM independent of the Hubble tension ( https://arxiv.org/abs/2305.08895 ).
Nice paper from Kyoto today, https://arxiv.org/abs/2309.02288, emphasizing that small-scale inhomogeneities are unlikely to play a relevant role in understanding the Hubble tension. This also follows from classic papers like BNSZ’s https://arxiv.org/abs/1004.2488 and Peebles https://arxiv.org/abs/0910.5142
Nice informative result in today’s paper; the old Early Dark Energy model struggles to address the S8 tension (https://arxiv.org/abs/2309.00401). This singles out New Early Dark Energy, a triggered phase transition in the dark sector, as a possible minimal resolution to both the H0 and the S8 tensions — see f.ex. https://arxiv.org/abs/2305.08895.
First Sloth in space! Zero-G indicator on today’s mission to the space station was a Sloth 🦥
Quote from today’s review of the local H0 measurements: JWST “observations provide the strongest evidence yet that systematic errors in HST Cepheid photometry do not play a significant role in the present Hubble Tension”: https://arxiv.org/abs/2308.10954
Groningen group with a new paper *not* finding evidence of unknown systematics being the source of the Hubble tension. This further strengthens the case for early times (pre-recombination) new physics, like New Early Dark Energy (NEDE): https://arxiv.org/abs/2308.05157
A reminder not to believe we know it all and not to stop exploring the wonders that nature might hide for us.
Niels Bohr, in conversation with Robert J. Oppenheimer.
