Abstract
We study the coupling of massive fermions to the quantum mechanical dynamics of spacetime emerging from the spinfoam approach in three dimensions. We first recall the classical theory before constructing a spinfoam model of quantum gravity coupled to spinors. The technique used is based on a finite expansion in inverse fermion masses leading to the computation of the vacuum to vacuum transition amplitude of the theory. The path integral is derived as a sum over closed fermionic loops wrapping around the spinfoam. The effects of quantum torsion are realised as a modification of the intertwining operators assigned to the edges of the two-complex, in accordance with loop quantum gravity. The creation of non-trivial curvature is modelled by a modification of the pure gravity vertex amplitudes. The appendix contains a review of the geometrical and algebraic structures underlying the classical coupling of fermions to three dimensional gravity.
Similar content being viewed by others
References
Perez A. (2003). Spin foam models for quantum gravity. Class. Quant. Grav. 20: R43 gr-qc/0301113
Oriti D. (2001). Spacetime geometry from algebra: Spin foam models for non-perturbative quantum gravity. Rept. Prog. Phys. 64: 1489–1544 gr-qc/0106091
Baez J.C. (2000). An introduction to spin foam models of BF theory and quantum gravity. Lect. Notes Phys. 543: 25–94 gr-qc/9905087
Baez J.C. (1998). Spin foam models. Class. Quant. Grav. 15: 1827–1858 gr-qc/9709052
Misner C. (1957). Feynman quantization of General Relativity. Rev. Mod. Phys. 29: 497
Hawking, S.W.: The path-integral approach to quantum gravity. In: Hawking, S.W., Israel, W. (eds.) General Relativity: An Einstein Centenary Survey. Cambridge University Press, Cambridge (1979)
Perez, A.: The spin-foam-representation of loop quantum gravity. (2006) gr-qc/0601095
Rovelli C. (2004). Quantum Gravity. Cambridge University Press, Cambridge
Thiemann, T.: Modern Canonical Quantum General Relativity. Cambridge University Press, Cambridge (to appear)
Ashtekar A. and Lewandowski J. (2004). Background independent quantum gravity: A status report. Class. Quant. Grav. 21: R53 gr-qc/0404018
Perez, A.: Introduction to loop quantum gravity and spin foams (2004) gr-qc/0409061
Plebanski J.F. (1977). On the separation of Einstein substructures. J. Math. Phys. 12: 2511
Barrett J.W. and Crane L. (1998). Relativistic spin networks and quantum gravity. J. Math. Phys. 39: 3296–3302 gr-qc/9709028
Barrett J.W. and Crane L. (2000). A Lorentzian signature model for quantum general relativity. Class. Quant. Grav. 17: 3101–3118 gr-qc/9904025
Freidel L., Krasnov K. and Puzio R. (1999). BF description of higher-dimensional gravity theories. Adv. Theor. Math. Phys. 3: 1289–1324 hep-th/9901069
Boulatov D.V. (1992). A Model of three-dimensional lattice gravity. Mod. Phys. Lett. A 7: 1629–1646 hep-th/9202074
Ooguri H. (1992). Topological lattice models in four-dimensions. Mod. Phys. Lett. A 7: 2799–2810 hep-th/9205090
Freidel L. (2005). Group field theory: An overview. Int. J. Theor. Phys. 44: 1769–1783 hep-th/0505016
Oriti, D.: Quantum gravity as a quantum field theory of simplicial geometry (2005) gr-qc/0512103
Morales-Tecotl H. and Rovelli C. (1994). Fermions in quantum gravity. Phys. Rev. Lett. 72: 3642–3645
Baez J.C. and Krasnov K. (1998). Quantization of diffeomorphism invariant theories with fermions. J. Math. Phys. 39: 1251–1271
Thiemann T. (1998). Kinematical Hilbert spaces for fermionic and Higgs quantum field theories. Class. Quant. Grav. 15: 1487–1512
Smolin, L.: Fermions and topology. gr-qc/9404010
Chakraborty S. and Peldan P. (1994). Gravity and Yang–Mills theory: two faces of the same theory? Int. J. Mod. Phys. D 3: 695–722 gr-qc/9403002
Chakraborty S. and Peldan P. (1994). Towards a unification of gravity and Yang–Mills theory. Phys. Rev. Lett. 73: 1195–1198 gr-qc/9401028
Gambini, R., Olson, S., Pullin, J.: Unified model of loop quantum gravity and matter. gr-qc/0409045
Crane, L.: A new approach to the geometrization of matter. gr-qc/0110060
Crane, L.: Hypergravity and categorical Feynmanology. gr-qc/0004043
Mikovic A. (2002). Spin foam models of matter coupled to gravity. Class. Quant. Grav. 19: 2335
Livine E.R. and Oeckl R. (2004). Three-dimensional quantum supergravity and supersymmetric spin foam models. Adv. Theor. Math. Phys. 7: 951–1001 hep-th/0307251
Mikovic A. (2003). Spin foam models of Yang–Mills theory coupled to gravity. Class. Quant. Grav. 20: 239
Oriti D. and Pfeiffer H. (2002). A spin foam model for pure gauge theory coupled to quantum gravity. Phys. Rev. D 66: 124010
Conrady, F.: Geometric spin foams, Yang–Mills theory and background-independent models. gr-qc/0504059
Freidel L. and Louapre D. (2004). Ponzano-Regge model revisited I: Gauge fixing, observables and interacting spinning particles. Class. Quant. Grav. 21: 5685–5726
Noui K. and Perez A. (2005). Three-dimensional loop quantum gravity: coupling to point particles. Class. Quant. Grav. 22: 4489–4514
de Sousa Gerbert P. (1990). On spin and (quantum) gravity in (2+1)-dimensions. Nucl. Phys. B 346: 440–472
Freidel, L., Oriti, D., Ryan, J.: A group field theory for 3-D quantum gravity coupled to a scalar field. gr-qc/0506067
Oriti, D., Ryan, J.: Group field theory formulation of 3d quantum gravity coupled to matter fields. gr-qc/0602010
Krasnov, K.: Quantum gravity with matter via group field theory. hep-th/0505174
Barrett, J.W.: Feynman diagrams coupled to three-dimensional quantum gravity. gr-qc/0502048
Baratin, A., Freidel, L.: Hidden quantum gravity in 3d Feynman diagrams. gr-qc/0604016
Freidel, L., Livine, E.R.: Effective 3d quantum gravity and non-commutative quantum field theory. hep-th/0512113
Freidel L. and Livine E.R. (2006). Ponzano-Regge model revisited. III: Feynman diagrams and effective field theory. Class. Quant. Grav. 23: 2021–2062 hep-th/0502106
Baez, J.C., Perez, A.: Quantization of strings and branes coupled to BF theory. gr-qc/0605087
Fairbairn, W.J., Perez, A.: Quantization of strings and branes coupled to BF theory: Physical scalar product and spinfoam models (in preparation)
Freidel, L., Kowalski-Glikman, J., Starodubtsev, A.: Particles as Wilson lines of gravitational field. gr-qc/0607014
Matschull H.-J. and Welling M. (1998). Quantum mechanics of a point particle in 2+1 dimensional gravity. Class. Quant. Grav. 15: 2981–3030 gr-qc/9708054
Choquet-Bruhat, Y.: Spin 1/2 fields in arbitrary dimensions and the Einstein-Cartan theory. In: Rindler, W., Trautman, A. (eds.) Gravitation and Geometry – A volume in honour of Ivor Robinson. pp. 83–106 (1989)
Hehl F.W., von der Heyde P. and Kerlick G.D. (1976). General relativity with spin and torsion: Foundations and prospects. Rev. Mod. Phys. 48: 393–419
Ponzano G. and Regge T. (1968). Semiclassical limit of Racah coefficients. Spectroscopic and group theoretical methods in physics. North-Holland Publ., Amsterdam
Reisenberger M.P. (1997). A left-handed simplicial action for Euclidean general relativity. Class. Quant. Grav. 14: 1753–1770 gr-qc/9609002
Seiler E. (1982). Gauge theories as a problem of constructive quantum field theory and statistical mechanics. Lect. Notes Phys. 159: 1–192
Fröhlich, J.: Regge calculus and discretized gravitational functional integrals. In: Frölich, J. (ed.) Non-perturbative quantum field theory, pp. 523–545 (1994)
Schmitt T. (1997). Supergeometry and quantum field theory, or: What is a classical configuration? Rev. Math. Phys. 9: 993–1052 hep-th/9607132
DeWitt, B.: Supermanifolds. (Cambridge Monographs on Mathematical Physics), 1984
Freidel L. and Krasnov K. (1999). Spin foam models and the classical action principle. Adv. Theor. Math. Phys. 2: 1183–1247 hep-th/9807092
Christ N.H., Friedberg R. and Lee T.D. (1982). Weights of links and plaquettes in a random lattice. Nucl. Phys. B 210: 337
Ren H.-C. (1988). Matter fields in lattice gravity. Nucl. Phys. B 301: 661
Berezin F.A. (1966). The Method of Second Quantization, (Pure & Appl. Phys. 24). Academic, New York
Wilson K.G. (1974). Confinement of quarks. Phys. Rev. D 10: 2445–2459
Osterwalder K. and Seiler E. (1978). Gauge field theories on the lattice. Ann. Phys. 110: 440
Stamatescu I.O. (1982). Note on the lattice fermionic determinant. Phys. Rev. D 25: 1130
Bogacz L., Burda Z., Jurkiewicz J., Krzywicki A., Petersen C. and Petersson B. (2001). Dirac operator and Ising model on a compact 2D random lattice. Acta Phys. Polon. B 32: 4121–4168 hep-lat/0110063
Bogacz L., Burda Z. and Jurkiewicz J. (2003). Fermions in 2D Lorentzian quantum gravity. Acta Phys. Polon. B 34: 3987–4000 hep-lat/0306033
Wigner E.P. (1959). Group Theory and its application to the quantum mechanics of atomic spectra. Academic, New York
Baez J.C. and Barrett J.W. (1999). The quantum tetrahedron in 3 and 4 dimensions. Adv. Theor. Math. Phys. 3: 815–850 gr-qc/9903060
Turaev V.G. and Viro O.Y. (1992). State sum invariants of 3 manifolds and quantum 6j symbols.. Topology 31: 865–902
Mikovic, A.: Tetrade spin foam model (2005) gr-qc/0504131
Capovilla R., Jacobson T., Dell J. and Mason L. (1991). Selfdual two forms and gravity. Class. Quant. Grav. 8: 41–57
Modesto L. and Rovelli C. (2005). Particle scattering in loop quantum gravity. Phys. Rev. Lett. 95: 191–301 gr-qc/0502036
Rovelli, C.: Graviton propagator from background-independent quantum gravity (2005) gr-qc/0508124
Speziale S. (2006). Towards the graviton from spinfoams: The 3d toy model. JHEP 05: 039 gr-qc/0512102
Bianchi, E., Modesto, L., Rovelli, C.: Graviton propagator in loop quantum gravity (2006) gr-qc/0604044
Livine, E.R., Speziale, S., Willis, J.L.: Towards the graviton from spinfoams: Higher order corrections in the 3d toy model (2006) gr-qc/0605123
Livine, E.R., Speziale, S.: Group integral techniques for the spinfoam graviton propagator (2006) gr-qc/0608131
Coquereaux, R.: Clifford algebras, spinors and fundamental interactions: Twenty years after (2005) math-ph/0509040
Rausch de Traubenberg, M.: Clifford algebras in physics (2005) hep-th/0506011
Coquereaux, R.: Espace Fibrés et Connexions. (in French), avalable at http://www.cpt.univ-mrs.fr/coque/
Masson, T.: Géométrie différentielle, groupes et algèbres de Lie, fibrés et connexions. (in French), avalable at http://qcd.th.u-psud.fr/page_perso/Masson/
Trautman, A.: Clifford algebras and their representations. accepted for publication in the Encyclopedia of Mathematical Physics (2005)
Hehl F.W. and Von Der Heyde P. (1973). Spin and the structure of space-time. Ann. Poincare Phys. Theor. 19: 179–196
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Fairbairn, W.J. Fermions in three-dimensional spinfoam quantum gravity. Gen Relativ Gravit 39, 427–476 (2007). https://doi.org/10.1007/s10714-006-0395-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10714-006-0395-x