Gravity, Lorentz violation, and the standard model
Abstract
The role of the gravitational sector in the Lorentz and CPTviolating standardmodel extension (SME) is studied. A framework is developed for addressing this topic in the context of RiemannCartan spacetimes, which include as limiting cases the usual Riemann and Minkowski geometries. The methodology is first illustrated in the context of the QED extension in a RiemannCartan background. The full SME in this background is then considered, and the leadingorder terms in the SME action involving operators of mass dimension three and four are constructed. The incorporation of arbitrary Lorentz and CPT violation into general relativity and other theories of gravity based on RiemannCartan geometries is discussed. The dominant terms in the effective lowenergy action for the gravitational sector are provided, thereby completing the formulation of the leadingorder terms in the SME with gravity. Explicit Lorentz symmetry breaking is found to be incompatible with generic RiemannCartan geometries, but spontaneous Lorentz breaking evades this difficulty.
 Publication:

Physical Review D
 Pub Date:
 May 2004
 DOI:
 10.1103/PhysRevD.69.105009
 arXiv:
 arXiv:hepth/0312310
 Bibcode:
 2004PhRvD..69j5009K
 Keywords:

 11.30.Cp;
 04.50.+h;
 11.30.Er;
 12.60.i;
 Lorentz and Poincare invariance;
 Gravity in more than four dimensions KaluzaKlein theory unified field theories;
 alternative theories of gravity;
 Charge conjugation parity time reversal and other discrete symmetries;
 Models beyond the standard model;
 High Energy Physics  Theory;
 Astrophysics;
 General Relativity and Quantum Cosmology;
 High Energy Physics  Phenomenology
 EPrint:
 21 pages REVTeX, references added, accepted in Physical Review D