English

Compact objects in unimodular gravity

General Relativity and Quantum Cosmology 2019-09-11 v2

Abstract

Unimodular gravity provides a theoretical framework that allows for non-conservation of energy-momentum, with possible implications for the cosmological constant problem. It is then important to study the predictions of unimodular gravity in other gravitational regimes. In this work we study stellar dynamics under the assumption of non-conserved energy-momentum. We find that constant density objects can be as compact as Schwarzschild black holes. For polytropic objects, we find modifications due to the non-conservation of energy-momentum that lead to sizeable effects that could be constrained with observational data. Additionally, we revisit and clarify the Reissner-Nordstr\"om solution in unimodular gravity. We also study gravitational collapse and discuss possible implications for the growth of structure.

Keywords

Cite

@article{arxiv.1905.11253,
  title  = {Compact objects in unimodular gravity},
  author = {J. A. Astorga-Moreno and Javier Chagoya and J. C. Flores-Urbina and Miguel A. Garcia-Aspeitia},
  journal= {arXiv preprint arXiv:1905.11253},
  year   = {2019}
}

Comments

23 pages, 6 figures, title changed. Accepted for publication in JCAP