Séminaire Univers / |
| « A tale of two (or more) h's » |
|
Samuel Brieden |
| Solutions to the Hubble tension that modify physics before recombination typically impact both the sound horizon and the matter-radiation equality scale. Current large-scale structure galaxy data (LSS) from the BOSS and eBOSS surveys in combination with light element abundances from Big Bang Nucleosynthesis (BBN) can be combined to measure the Hubble constant H0 = 100 h [km s-1 Mpc-1] in two distinct ways. The first way relies on the calibration of the sound horizon through BBN in order to allow for a Hubble measurement in the BAO. The second way uses BBN and the broadband shape of the power spectrum in order to infer the matter-radiation equality scale. In this talk I present our latest results for both types of H0 measurements, using the recently developed ShapeFit methodology. I show new model consistency checks arising from this method within the LCDM framework and additionally discuss a selection of extended models. I will argue that any LCDM extension proposed to address the Hubble tension needs to modify consistently not only the sound horizon scale physics, but also the matter- radiation equality scale, in such a way that both h's are raised to the standard cosmic distance ladder determined value in a mutually consistent fashion. |
|
mardi 28 mars 2023 - 11:00 Amphithéâtre Henri Mineur Institut d'Astrophysique de Paris |
| Pages web du séminaire / Seminar's webpage |