Speaker
Description
The $H_0$-tension problem challenges our conventional application of general relativity to cosmology, otherwise well-described by FRLW universes in terms a Hubble parameter $H(z)$ and a deceleration parameter $q(z)$. A finite dark energy density is expected from the Sitter temperature associated with the de Sitter background scale of acceleration $a_{dS}=cH$, where $c$ is the velocity of light. Normalizing the propagator by the total phase of the Hubble horizon, this predicts a dynamical dark energy $\Lambda = g(1-q)H^2$, where $g=1-\xi\alpha<1$ refers to a gravitational coupling constant modified on the order of the fine-structure constant $\alpha$. Preserving the astronomical age of the Universe and the BAO, we infer $\xi =0.49\pm 0.1$. Specifically, $\xi =1/2$ predicts $H_0= (73.37\pm 0.54)$km/s/Mpc (van Putten, 2021, PLB, 823, 136737) consistent with $H_0=(73.30\pm1.04)$km/s/Mpc of the Local Distance Ladder (Riess et al. 2022, ApJ, 934, L7).
