Emergent four-dimensional linearized gravity from a spin foam model
Han M, Huang Z, Zipfel A (2019)
Publication Type: Journal article
Publication year: 2019
Journal
Book Volume: 100
Journal Issue: 2
DOI: 10.1103/PhysRevD.100.024060
Abstract
Spin foam models (SFMs) are covariant formulations of loop quantum gravity (LQG) in four dimensions. This work studies the perturbations of SFMs on a flat background. It demonstrates for the first time that smooth curved spacetime geometries satisfying the Einstein equation can emerge from discrete SFMs under an appropriate low energy limit, which corresponds to a semiclassical continuum limit of SFMs. In particular, we show that the low energy excitations of SFMs on a flat background give all smooth solutions of linearized Einstein equations (spin-2 gravitons). This indicates that at the linearized level, classical Einstein gravity can arise as a low energy effective theory from SFMs. Thus our result heightens the confidence that covariant LQG is a consistent theory of quantum gravity. As a key technical tool, a regularization/deformation of the SFM is employed in the derivation. The deformation parameter delta becomes a coupling constant of a higher curvature correction term to Einstein gravity from SFM.
Authors with CRIS profile
Involved external institutions
United States (USA) (US)How to cite
APA:
Han, M., Huang, Z., & Zipfel, A. (2019). Emergent four-dimensional linearized gravity from a spin foam model. Physical Review D, 100(2). https://dx.doi.org/10.1103/PhysRevD.100.024060
MLA:
Han, Muxin, Zichang Huang, and Antonia Zipfel. "Emergent four-dimensional linearized gravity from a spin foam model." Physical Review D 100.2 (2019).
BibTeX: Download