Scalar field as a null dust
General Relativity and Quantum Cosmology
2019-05-01 v1
Abstract
We show that a canonical, minimally coupled scalar field which is non-self interacting and massless is equivalent to a null dust fluid (whether it is a test or a gravitating field), in a spacetime region in which its gradient is null. Under similar conditions, the gravitating and nonminimally coupled Brans-Dicke-like scalar of scalar-tensor gravity, instead, cannot be represented as a null dust unless its gradient is also a Killing vector field.
Keywords
Cite
@article{arxiv.1812.06457,
title = {Scalar field as a null dust},
author = {Valerio Faraoni and Jeremy Côté},
journal= {arXiv preprint arXiv:1812.06457},
year = {2019}
}