English

Global Monopole in Palatini f(R) gravity

General Relativity and Quantum Cosmology 2019-04-03 v2

Abstract

We consider the space-time metric generated by a global monopole in an extension of General Relativity (GR) of the form f(R)=RλR2f(\mathcal{R})=\mathcal{R}-\lambda \mathcal{R}^2. The theory is formulated in the metric-affine (or Palatini) formalism and exact analytical solutions are obtained. For λ<0\lambda<0, one finds that the solution has the same characteristics as the Schwarzschild black hole with a monopole charge in Einstein's GR. For λ>0\lambda>0, instead, the metric is more closely related to the Reissner-Nordstr\"{o}m metric with a monopole charge and, in addition, it possesses a wormhole-like structure that allows for the geodesic completeness of the space-time. Our solution recovers the expected limits when λ=0\lambda=0 and also at the asymptotic far limit. The angular deflection of light in this spacetime in the weak field regime is also calculated.

Keywords

Cite

@article{arxiv.1812.00471,
  title  = {Global Monopole in Palatini f(R) gravity},
  author = {J. R. Nascimento and Gonzalo J. Olmo and A. Yu. Petrov and P. J. Porfirio and A. R. Soares},
  journal= {arXiv preprint arXiv:1812.00471},
  year   = {2019}
}

Comments

15 pages, version accepted to PRD