Quasilocal Center-of-Mass
Abstract
Gravitating systems have no well-defined local energy-momentum density. Various quasilocal proposals have been made, however the center-of-mass moment (COM) has generally been overlooked. Asymptotically flat graviating systems have 10 total conserved quantities associated with the Poincar{\'e} symmetry at infinity. In addition to energy-momentum and angular momentum (associated with translations and rotations) there is the boost quantity: the COM. A complete quasilocal formulation should include this quantity. Getting good values for the COM is a fairly strict requirement, imposing the most restrictive fall off conditions on the variables. We take a covariant Hamiltonian approach, associating Hamiltonian boundary terms with quasilocal quantities and boundary conditions. Unlike several others, our {\it covariant symplectic} quasilocal expressions do have the proper asymptotic form for all 10 quantities.
Keywords
Cite
@article{arxiv.gr-qc/0403103,
title = {Quasilocal Center-of-Mass},
author = {James M. Nester and Feng-Feng Meng and Chiang-Mei Chen},
journal= {arXiv preprint arXiv:gr-qc/0403103},
year = {2007}
}
Comments
4 pages, contribution to the 6th International Conference of Gravitation and Astrophysics, Seoul, 2003 (revised version)