Lavinia Heisenberg, Jann Zosso

We establish radiative stability of all generalized Proca theories. While standard powercounting arguments would conclude otherwise, we find non-trivial cancellations of leading order corrections by explicit computation of divergent one-loop diagrams up to four-point. These results are crosschecked against an effective action based generalized Schwinger-DeWitt method. Further, these cancellations are understood as coming from the specific structure of the theory through a decoupling limit analysis which at the same time allows for an extension of the results to all orders.

Ke Wang, Lu Chen

The Newton's constant have observational effects on both the CMB power spectra and the light curves of SNIa. We use the Planck data, BAO data and the SNIa measurement to constrain the Newton's constant $G$ during the CMB epoch and the redshift ranges of PANTHEON samples, and find no evidence indicating that $G$ is varying with redshift. By extending the $\Lambda$CDM model with a free parameter $G$, we get $H_0=70.54 \pm 0.95$ km s$^{-1}$ Mpc$^{-1}$ at 68$\%$ C.L. and alleviate the $H_0$ tension between R19 and Planck+BAO data slightly, to $2\sigma$.