Quantum gravity and the standard model
Abstract
We show that a class of backgroundindependent models of quantum spacetime have local excitations that can be mapped to the firstgeneration fermions of the standard model of particle physics. These states propagate coherently as they can be shown to be noiseless subsystems of the microscopic quantum dynamics (Kribs and Markopoulou 2005 Preprint grqc/0510052, Markopoulou and Poulin unpublished). These are identified in terms of certain patterns of braiding of graphs, thus giving a quantum gravitational foundation for the topological preon model proposed by BilsonThompson (2005 Preprint hepph/0503213). These results apply to a large class of theories in which the Hilbert space has a basis of states given by ribbon graphs embedded in a threedimensional manifold up to diffeomorphisms, and the dynamics is given by local moves on the graphs, such as arise in the representation theory of quantum groups. For such models, matter appears to be already included in the microscopic kinematics and dynamics.
 Publication:

Classical and Quantum Gravity
 Pub Date:
 August 2007
 DOI:
 10.1088/02649381/24/16/002
 arXiv:
 arXiv:hepth/0603022
 Bibcode:
 2007CQGra..24.3975B
 Keywords:

 High Energy Physics  Theory
 EPrint:
 12 pages, 21 figures, improved presentation, results unchanged