Vacuum Condensate Picture of Quantum Gravity

Abstract

In quantum gravity perturbation theory in Newton's constant G is known to be badly divergent, and as a result not very useful. Nevertheless some of the most interesting phenomena in physics are often associated with non-analytic behavior in the coupling constant and the existence of nontrivial quantum condensates. It is therefore possible that pathologies encountered in the case of gravity are more likely the result of inadequate analytical treatment, and not necessarily a reflection of some intrinsic insurmountable problem. The nonperturbative treatment of quantum gravity via the Regge-Wheeler lattice path integral formulation reveals the existence of a new phase involving a nontrivial gravitational vacuum condensate, and a new set of scaling exponents characterizing both the running of G and the long-distance behavior of invariant correlation functions. The appearance of such a gravitational condensate is viewed as analogous to the (equally nonperturbative) gluon and chiral condensates known to describe the physical vacuum of QCD. The resulting quantum theory of gravity is highly constrained, and its physical predictions are found to depend only on one adjustable parameter, a genuinely nonperturbative scale xi in many ways analogous to the scaling violation parameter Lambda MSbar of QCD. Recent results point to significant deviations from classical gravity on distance scales approaching the effective infrared cutoff set by the observed cosmological constant. Such subtle quantum effects are expected to be initially small on current cosmological scales, but could become detectable in future high precision satellite experiments.

72 pages, 7 figures. Typos fixed, references added. Conforms to published version. arXiv admin note: text overlap with arXiv:1506.07795

References in corpus (13)

• Measuring the dark side (with weak lensing)
• Cluster Constraints on f(R) Gravity
• Bimetric Renormalization Group Flows in Quantum Einstein Gravity
• Light Hadron Masses from Lattice QCD
• En route to Background Independence: Broken split-symmetry, and how to restore it with bi-metric average actions
• Direct determination of the strange and light quark condensates from full lattice QCD
• Gauges and functional measures in quantum gravity I: Einstein theory
• A Multi-Parameter Investigation of Gravitational Slip
• Running of Newton's constant and non integer powers of the d'Alembertian
• Gravitational Wilson Loop and Large Scale Curvature
• Renormalization Group Running of Newton's G: The Static Isotropic Case
• High-Energy Gravitational Scattering and Bose-Einstein Condensates of Gravitons
• Gravitational Fluctuations as an Alternative to Inflation

Cited by in corpus (10)

• Gravity in the infrared and effective nonlocal models
• Complex, Lorentzian, and Euclidean simplicial quantum gravity: numerical methods and physical prospects
• The Gravity of the Classical Klein-Gordon field
• Light ray fluctuations in simplicial quantum gravity
• Gravitational Fluctuations as an Alternative to Inflation II. CMB Angular Power Spectrum
• Quantum metrics with very low action in $R+R^2$ gravity
• Three models of non-perturbative quantum-gravitational binding
• Can we detect the quantum nature of weak gravitational fields?
• Metrics with zero and almost-zero Einstein action in quantum gravity
• Quantum-only metrics in spherically symmetric gravity