Emergent four-dimensional linearized gravity from a spin foam model

Journal article

Publication Details

Author(s): Han M, Huang Z, Zipfel A
Journal: Physical Review D
Publication year: 2019
Volume: 100
Journal issue: 2
ISSN: 2470-0010
eISSN: 2470-0029


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.

FAU Authors / FAU Editors

Han, Muxin Dr.
Chair for Theoretical Physics III (Quantum Gravity)

External institutions with authors

Florida Atlantic University

How to cite

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

Han, Muxin, Zichang Huang, and Antonia Zipfel. "Emergent four-dimensional linearized gravity from a spin foam model." Physical Review D 100.2 (2019).


Last updated on 2019-09-08 at 16:53