Towards effective actions for the continuum limit of spin foams

Abstract

Spin foams arise from a quantization of classical gravity expressed via the Plebanski action. Key open questions related to the continuum limit of spin foams are whether general relativity is reproduced and what type of corrections could emerge. As a central component for spin foam dynamics, recent results on the continuum limit of the Area Regge action suggest a close relation with actions for area metrics instead of a length metric. Inspired by these results, within the framework of modified Plebanski theory we construct a family of candidate actions for area metrics. These actions are expected to describe the continuum limit of spin foams and provide a starting point to explore phenomenological aspects of the large-scale dynamics of spin foams. More generally, they set the stage for exploring consequences of an enlargement of the configuration space for gravity from length to area metrics. The actions we construct lead to an effective action for the length metric, describing a non-local and ghost-free version of Einstein-Weyl gravity.

17 pages + references; v2: eq. (6.17) corrected

References in corpus (27)

• LQG vertex with finite Immirzi parameter
• A New Spin Foam Model for 4d Gravity
• The loop-quantum-gravity vertex-amplitude
• Black Holes in Higher-Derivative Gravity
• Consistently Solving the Simplicity Constraints for Spinfoam Quantum Gravity
• Area-angle variables for general relativity
• Effective Spin Foam Models for Four-Dimensional Quantum Gravity
• Effective Spin Foam Models for Lorentzian Quantum Gravity
• Gauge invariant perturbations around symmetry reduced sectors of general relativity: applications to cosmology
• Coarse graining free theories with gauge symmetries: the linearized case
• On deformations of Ashtekar's constraint algebra
• Renormalizable Non-Metric Quantum Gravity?
• Bi-metric theory of gravity from the non-chiral Plebanski action
• Spinfoam on Lefschetz Thimble: Markov Chain Monte-Carlo Computation of Lorentzian Spinfoam Propagator
• Discrete gravity dynamics from effective spin foams
• Hamiltonian Analysis of non-chiral Plebanski Theory and its Generalizations
• Plebanski gravity without the simplicity constraints
• From spin foams to area metric dynamics to gravitons
• Addendum: EPRL/FK Asymptotics and the Flatness Problem
• Complex, Lorentzian, and Euclidean simplicial quantum gravity: numerical methods and physical prospects
• Geometry for the accelerating universe
• Modified gravity without new degrees of freedom
• Non-symmetric wormholes and localized Big Rip singularities in Einstein-Weyl gravity
• Twisted geometries are area-metric geometries
• Properties of the Hamiltonian Renormalisation and its application to quantum mechanics on the circle
• Modified Graviton Dynamics From Spin Foams: The Area Regge Action
• Complex actions and causality violations: Applications to Lorentzian quantum cosmology

Cited by in corpus (12)

• From spin foams to area metric dynamics to gravitons
• Suppression of spacetime singularities in quantum gravity
• Scale-invariance at the core of quantum black holes
• Lorentzian quantum cosmology from effective spin foams
• Visions in Quantum Gravity
• Twisted geometries are area-metric geometries
• Area-metric gravity revisited
• Spinfoams: Foundations
• A non-local way around the no-global-symmetries conjecture in quantum gravity?
• Precision predictions of Starobinsky inflation with self-consistent Weyl-squared corrections
• From area metric backgrounds to the cosmological constant and corrections to the Polyakov action
• Charting GLOBs in Asymptotically Safe Gravity