Stellar configurations in f(R) theories of gravity
| dc.creator | Henttunen, K. | |
| dc.creator | Multamaki, T. | |
| dc.creator | Vilja, I. | |
| dc.date | 2007-05-18 | |
| dc.date | 2007-05-28 | |
| dc.date.accessioned | 2026-07-07T12:13:31Z | |
| dc.date.available | 2026-07-07T12:13:31Z | |
| dc.description | We study stellar configurations and the space-time around them in metric $f(R)$ theories of gravity. In particular, we focus on the polytropic model of the Sun in the $f(R)=R-μ^4/R$ model. We show how the stellar configuration in the $f(R)$ theory can, by appropriate initial conditions, be selected to be equal to that described by the Lane-Emden -equation and how a simple scaling relation exists between the solutions. We also derive the correct solution analytically near the center of the star in $f(R)$ theory. Previous analytical and numerical results are confirmed, indicating that the space-time around the Sun is incompatible with Solar System constraints on the properties of gravity. Numerical work shows that stellar configurations, with a regular metric at the center, lead to $γ_{PPN}\simeq1/2$ outside the star ie. the Schwarzschild-de Sitter -space-time is not the correct vacuum solution for such configurations. Conversely, by selecting the Schwarzschild-de Sitter -metric as the outside solution, we find that the stellar configuration is unchanged but the metric is irregular at the center. The possibility of constructing a $f(R)$ theory compatible with the Solar System experiments and possible new constraints arising from the radius-mass -relation of stellar objects is discussed. | |
| dc.description | 8 pages, 7 figures; typos corrected, reference added | |
| dc.identifier | https://arxiv.org/abs/0705.2683 | |
| dc.identifier | http://arxiv.org/abs/0705.2683 | |
| dc.identifier | Phys.Rev.D77:024040,2008 | |
| dc.identifier | doi:10.1103/PhysRevD.77.024040 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/210874 | |
| dc.subject | Astrophysics | |
| dc.subject | General Relativity and Quantum Cosmology | |
| dc.title | Stellar configurations in f(R) theories of gravity | |
| dc.type | text |