Quantum gravity

Quantum process

Discrete mathematics

Physics

Gravitation

Hořava–Lifshitz gravity

Quantum dynamics

Mathematics

Mathematical physics

Semiclassical gravity

General relativity

Unimodular matrix

Theoretical physics

Euclidean quantum gravity

Quantum mechanics

Loop quantum gravity

Asymptotic safety in quantum gravity

Classical mechanics

Quantum

Journal of High Energy Physics

Constraining quantum gravity from observations is a challenge. We expand on the idea that the interplay of quantum gravity with matter could be key to meeting this challenge. Thus, we set out to confront different potential candidates for quantum gravity -- unimodular asymptotic safety, Weyl-squared gravity and asymptotically safe gravity -- with constraints arising from demanding an ultraviolet complete Standard Model. Specifically, we show that within approximations, demanding that quantum gravity solves the Landau-pole problems in Abelian gauge couplings and Yukawa couplings strongly constrains the viable gravitational parameter space. In the case of Weyl-squared gravity with a dimensionless gravitational coupling, we also investigate whether the gravitational contribution to beta functions in the matter sector calculated from functional Renormalization Group techniques is universal, by studying the dependence on the regulator, metric field parameterization and choice of gauge.

A link that matters: towards phenomenological tests of unimodular asymptotic safety