Quantum Gravity Asymptotic Safety from 2D Universal Regime and Smooth Transition to Dual Superstrings
Stéphane Maes
Abstract
In the context of our work on multi-fold universes, and the emergence of gravity from entanglement, we argued that quantum gravity is asymptotically safe in multi-fold universe, as well as in the real universe, where the arguments rely either on the belief that multi-fold mechanisms correctly model these aspects, or on arguments captured in the literature by asymptotic safe quantum gravity aficionados. We discussed the consequences of asymptotic safety: the incompatibility of supersymmetry, and superstrings, or M-theory, with the Standard Model (SM) or SMG (The Standard Model with non-negligible gravity effects at the SM scales). On the other hand, string afficionados, and others to be fair, view asymptotic safety claims for gravity with skepticism, to say the least. Arguments that gravity would be asymptotically safe, and incompatible with superstrings, have not reduced their claims of supremacy, or viability of the superstrings theory. Indeed, asymptotic safety is often treated as heretic, derided, or labeled by a few, as non-sensical, or fundamentally mistaken. It is despite several hints that asymptotic safety might indeed apply to General Relativity (GR)-based quantum gravity. Having accumulated more and more arguments that position superstrings with respect to multi-fold universes, and that seem to explain some of their challenges, we wonder if we could settle the asymptotic safety once and for all, using conventional Physis, i.e. not multi-fold, or even better, stringy arguments, just as we recently did, in another paper, for de Sitter vacua, and the string swampland, and of course, taking such latter results into account.In this paper, we present arguments that justify, non-perturbatively, the asymptotic safety of gravity in a conventional universe, and in a multi-fold universe. More surprisingly, we encounter a possible touch point between the resulting UV fixed point, and gravity dimensional reduction to 2D processes, where the cosmological coupling in the presence of matter may first be negative, and the UV fixed point might therefore potentially also be described by, or emerge from, superstrings. There are possible smooth transitions between AdS dual and spacetime in the conventional, superstrings and multi-fold cases. However, we do not know if that can be reconciled with the other incompatibilities between SM and superstrings, resulting from the asymptotic safety, which might still exist when considering, the trajectories of the couplings running away from the UV fixed point. In order to be non-perturbative, our approach provides arguments and microscopic justifications for the effects of running the gravitational couplings.In multi-fold universes, a new phenomena has been identified: short range entanglement between concretized spacetime locations that contribute negatively to the cosmological constant at very small scales (in 2D regimes).