Affine Symmetry, Geodesics, and Homogeneous Spacetimes
Abstract
We show that the conservation laws for the geodesic equation which are associated to affine symmetries can be obtained from symmetries of the Lagrangian for affinely parametrized geodesics according to Noether's theorem, in contrast to claims found in the literature. In particular, using Aminova's classification of affine motions of Lorentzian manifolds, we show in detail how affine motions define generalized symmetries of the geodesic Lagrangian. We compute all infinitesimal proper affine symmetries and the corresponding geodesic conservation laws for all homogeneous solutions to the Einstein field equations in four spacetime dimensions with each of the following energy-momentum contents: vacuum, cosmological constant, perfect fluid, pure radiation, and homogeneous electromagnetic fields.
Keywords
Cite
@article{arxiv.1807.08180,
title = {Affine Symmetry, Geodesics, and Homogeneous Spacetimes},
author = {David Maughan and Charles Torre},
journal= {arXiv preprint arXiv:1807.08180},
year = {2018}
}
Comments
To appear in General Relativity and Gravitation. Version 2 corrects some typographical errors