Nonvanishing gravitational contribution to matter beta functions for vanishing dimensionful regulators

Abstract

We explore the effect of quantum gravity on matter within a Renormalization Group framework. First, our results provide an explicit example of how misleading conclusions can be drawn by analyzing the gravitational contributions to beta functions, instead of analyzing universal quantities, such as critical exponents, that can be extracted from the beta functions. This could be key to explain differences between perturbative studies and Functional Renormalization Group studies. Second, we strengthen the evidence that asymptotically safe gravity could generate a predictive ultraviolet completion for matter theories with gauge interactions, even in the limit of vanishing dimensionful regulator function. We also find that the situation can be more subtle with higher-order, gravity-induced matter interactions.

Weak-gravity bound in asymptotically safe gravity-gauge systems

“…( 4). More generally speaking, there is strong evidence that at an asymptotically safe fixed point for gravity and matter, all couplings that respect the symmetries of the system, including matter selfinteractions [95,96,106,121,[124][125][126][127][128][129][145][146][147][148] and nonminimal interactions [116,126,127,129,149] are nonvanishing. In turn, those operators that break a symmetry of the system can consistently be set to zero, see, e.g., [107,129,137,138,[150][151][152].…”