Structure of neutron stars in R-squared gravity
The effects implied for the structure of compact objects by the modification of General Relativity produced by the generalization of the Lagrangian density to the form R plus alpha R-squared, where R is the Ricci curvature scalar, have been recently explored. It seems likely that this squared-gravit...
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| Autores principales: | , , , |
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| Formato: | Articulo Preprint |
| Lenguaje: | Inglés |
| Publicado: |
2013
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| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/100776 https://ri.conicet.gov.ar/11336/4551 http://link.springer.com/article/10.1007%2Fs10714-013-1501-5 |
| Aporte de: |
| Sumario: | The effects implied for the structure of compact objects by the modification of General Relativity produced by the generalization of the Lagrangian density to the form R plus alpha R-squared, where R is the Ricci curvature scalar, have been recently explored. It seems likely that this squared-gravity may allow heavier Neutron Stars (NSs) than GR. In addition, these objects can be useful to constrain free parameters of modified-gravity theories. The differences between alternative gravity theories is enhanced in the strong gravitational regime. In this regime, because of the complexity of the field equations, perturbative methods become a good choice to treat the problem. Following previous works in the field, we performed a numerical integration of the structure equations that describe NSs in f(R)-gravity, recovering their mass-radius relations, but focusing on particular features that arise from this approach in the profiles of the NS interior.We show that these profiles run in correlation with the second-order derivative of the analytic approximation to the Equation of State (EoS), which leads to regions where the enclosed mass decreases with the radius in a counter-intuitive way. We reproduce all computations with a simple polytropic EoS to separate zeroth-order modified gravity effects. |
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