English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Recently, a fully covariant version of the theory of $F(T)$ torsion gravityhas been introduced (arXiv:1510.08432v2 [gr-qc]). In covariant $F(T)$ gravitythe Schwarzschild solution is not a vacuum solution for $F(T)\neq T$ andtherefore determining the spherically symmetric vacuum is an important openproblem. Within the covariant framework we perturbatively solve the sphericallysymmetric vacuum gravitational equations around the Schwarzschild solution forthe scenario with $F(T)=T + (\alpha/2)\, T^{2}$, representing the dominantterms in theories governed by Lagrangians analytic in the torsion scalar. Fromthis we compute the perihelion shift correction to solar system planetaryorbits as well as perturbative gravitational effects near neutron stars. Thisallows us to set an upper bound on the magnitude of the coupling constant,$\alpha$, which governs deviations from General Relativity. We find the boundon this nonlinear torsion coupling constant by specifically considering theuncertainty in the perihelion shift of Mercury. We also analyze a bound from asimilar comparison with the periastron orbit of the binary pulsar PSRJ0045-7319 as an independent check for consistency. Setting bounds on thedominant nonlinear coupling is important in determining if other effects in thesolar system or greater universe could be attributable to nonlinear torsion.

The Spherically Symmetric Vacuum in Covariant $F(T) = T + \frac{\alpha}{2}T^{2} + \mathcal{O}(T^{\gamma})$ Gravity Theory