Quantum Gravity: A Fluctuating Point of View

Frontiers in Physics

Jan M. Pawlowski¹  Manuel Reichert² 

[1] Heidelberg, Germany;Darmstadt, Germany;Odense, Denmark;Brighton, United Kingdom;

关键词: quantum gravity;    asymptotic safety;    background independence;    diffeomorphism invariance;    ward identities;   

DOI  :  10.3389/fphy.2020.551848

来源: Frontiers

【 摘 要 】

In this contribution, we discuss the asymptotic safety scenario for quantum gravity with a functional renormalization group approach that disentangles dynamical metric fluctuations from the background metric. We review the state of the art in pure gravity and general gravity–matter systems. This includes the discussion of results on the existence and properties of the asymptotically safe ultraviolet fixed point, full ultraviolet-infrared trajectories with classical gravity in the infrared, and the curvature dependence of couplings also in gravity–matter systems. The results in gravity–matter systems concern the ultraviolet stability of the fixed point and the dominance of gravity fluctuations in minimally coupled gravity–matter systems. Furthermore, we discuss important physics properties such as locality of the theory, diffeomorphism invariance, background independence, unitarity, and access to observables, as well as open challenges.

【 授权许可】

CC BY