Propagation equations for deformable test bodies with microstructure in extended theories of gravity

Journal Article · Mon Oct 15 04:00:00 EDT 2007 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.76.084025· OSTI ID:21032472

Puetzfeld, Dirk; Obukhov, Yuri N ^[1]

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1. Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029, 0315 Oslo (Norway)

We derive the equations of motion in metric-affine gravity by making use of the conservation laws obtained from Noether's theorem. The results are given in the form of propagation equations for the multipole decomposition of the matter sources in metric-affine gravity, i.e., the canonical energy-momentum current and the hypermomentum current. In particular, the propagation equations allow for a derivation of the equations of motion of test particles in this generalized gravity theory, and allow for direct identification of the couplings between the matter currents and the gauge gravitational field strengths of the theory, namely, the curvature, the torsion, and the nonmetricity. We demonstrate that the possible non-Riemannian spacetime geometry can only be detected with the help of the test bodies that are formed of matter with microstructure. Ordinary gravitating matter, i.e., matter without microscopic internal degrees of freedom, can probe only the Riemannian spacetime geometry. Thereby, we generalize previous results of general relativity and Poincare gauge theory.

• OSTI ID: 21032472
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 8 Vol. 76; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CONSERVATION LAWS
COSMOLOGY
DEGREES OF FREEDOM
EQUATIONS OF MOTION
GAUGE INVARIANCE
GENERAL RELATIVITY THEORY
GEOMETRY
GRAVITATION
GRAVITATIONAL FIELDS
MICROSTRUCTURE
SPACE-TIME
TEST PARTICLES
TORSION