ACADSTAFF UGM
| Title | : | The formulation of f(R)-gravity on singular semi-Riemannian manifolds |
| Author | : |
IQBAL ROBIYANA (1) Dr.rer.nat. Muhammad Farchani Rosyid, M.Si. (2) |
| Date | : | 2019 |
| Keyword | : | - - |
| Abstract | : | In singular semi-Riemannian manifolds, the metric is allowed to be degenerate, i.e. it is not necessarily non-degenerate. The formulation of f(R)-gravity on this kind of manifold has been studied. The field equation is obtained via variational principle approach. The quantities which is involved in the formulation is a smooth quantity even when the metric becomes degenerate. These quantities are the densitized energy-momentum tensor, the Ricci curvature tensor, and the arbitrary function of scalar curvature. The resulting filed equation is a more general field equation. It reduces to the standard field equation when the metric is non-degenerate. The extension of the modified Friedmann equations has also been obtained. The generalized mass (energy) density and the generalized pressure density can be constructed based on the definition of the densitized energy-momentum tensor. These quantities remain smooth even when the metric is degenerate. The modified-f(R) Schwarzschild black holes has also been considered. By coordinate transformation, the metric which is semi-regular has been obtained. The consequences of this formulation to the spacetime singularity has also been discussed. |
| Group of Knowledge | : | Fisika |
| Original Language | : | English |
| Level | : | Internasional |
| Status | : |
Published
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