The dynamics of vacuum, gravity and matter: Implications on the fundamental constants

Understand

The possibility that the vacuum energy density (VED), $\rho_{\rm vac}$, could be time dependent in the expanding Universe is intuitively more reasonable than just a rigid cosmological constant for the entire cosmic history.

• The dynamics of $\rho_{\rm vac}=\rho_{\rm vac}(H)$ as a function of the Hubble rate, $H(t)$, most likely contributes to alleviate cosmological problems and tensions, having also implications on the so-called fundamental `constants' of Nature, which should be slowly drifting with the cosmic expansion owing to the fluctuations of the quantum vacuum.
• This includes the gravitational `constant' $G$, but also the gauge and Yukawa couplings as well as the particle masses themselves (both of dark matter and baryonic matter).
• The subtle exchange of energy involved is the basis for the ``micro and macro connection''.