Localizing the energy and momentum of linear gravity

7th International Conference on Gravitation and Cosmology

Butcher, L.M.^1

Kavli Institute for Cosmology, Madingley Road, Cambridge, CB3 0HA, United Kingdom^1

关键词: Energy condition;    Exchange of energy;    General Relativity;    Gravitational energy;    Linear approximations;    Local description;    New approaches;    Second derivatives;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/484/1/012011/pdf
DOI  :  10.1088/1742-6596/484/1/012011

来源: IOP

【 摘 要 】

Although there is little doubt that gravitational waves exist and carry energy as they propagate, it has been notoriously difficult to explain where in spacetime this energy resides. We have summarized a new approach to the localization of gravitational energy-momentum, valid within the linear approximation to general relativity . Built around a local description of the exchange of energy-momentum between matter and linear gravity, the framework defines a unique symmetric gravitational energy-momentum tensor, free of second derivatives, and motivates a natural gauge-fixing programme, which renders the description unambiguous. Once the gauge has been fixed according to this programme, the gravitational energy-momentum tensor obeys the dominant energy condition: gravitational energy-density is never negative, and gravitational energy-flux is never spacelike.