Gravity beyond Einstein? Yes, but in which direction? (Demos Kazanas, 26/10/2021)
Channel: Academy of Athens
Date: 26/10/2021

Gravity beyond Einstein? Yes, but in which direction?

Demosthenes Kazanas
NASA Goddard Space Flight Center, Corresponding Member of the Academy of Athens

Abstract:

I provide the reasons behind a reconsideration of Einstein gravity, i.e. that which relies on the Hilbert – Einstein (HE) action. I review a proposal discussed thirty years ago by Philip Mannheim and myself, by enlarging the symmetries of the gravitational action to include local scale invariance of the geometry. I will present exact solutions of this theory and argue they provide besides the usual Newtonian and de Sitter terms one that represents a characteristic universal acceleration and discuss its astrophysical and otherwise applications and open questions. I will speculate that this theory forbids the presence of true black holes and discuss alternatives