Form Factors in Quantum Gravity - contrasting non-local, ghost-free gravity and Asymptotic Safety

Abstract

Form factors constitute the key building block when organising the gravitational dynamics in terms of a curvature expansion. They generalise the concept of momentum-dependent couplings to curved spacetime. Moreover, they may capture modifications of the gravitational interactions at high energy scales in a non-perturbative way. We briefly review the role of form factors in various quantum gravity programmes with special emphasis on non-local, ghost-free gravity and asymptotically safe gravity. In this context, we introduce a quantum gravity motivated scalar toy model, which demonstrates that Lorentzian asymptotic safety may be compatible with the causal propagation of gravitons.

References in corpus (10)

• The nonperturbative functional renormalization group and its applications
• Unitarity, stability and loops of unstable ghosts
• Quantum gravity: a fluctuating point of view
• Non-perturbative unitarity and fictitious ghosts in quantum gravity
• Bare Action and Regularized Functional Integral of Asymptotically Safe Quantum Gravity
• Finite Quantum Gravity Amplitudes -- no strings attached
• EPFL Lectures on General Relativity as a Quantum Field Theory
• Generalized ghost-free propagators in nonlocal field theories
• Quantum scale symmetry
• Reconstructing the graviton

Cited by in corpus (5)

• Quasinormal ringing of regular black holes in asymptotically safe gravity: the importance of overtones
• Effective action and black hole solutions in asymptotically safe quantum gravity
• Suppression of spacetime singularities in quantum gravity
• Shift-symmetric Horndeski gravity in the asymptotic-safety paradigm
• Lectures in Quantum Gravity