Constraints on perturbative f(R) gravity via neutron stars

By S. Arapoğlu, C. Deliduman, K. Ekşi. 2010

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We study the structure of neutron stars in perturbative f(R) gravity models with realistic equations of state. We obtain mass-radius relations in a gravity model of the form f(R) = R+αR2. We find that deviations from the results of general relativity, comparable to the variations due to using different equations of state (EoS'), are induced for |α| ~ 109 cm2. Some of the soft EoS' that are excluded within the framework of general relativity can be reconciled with the 2 solar mass neutron star recently observed for certain values of α within this range. For some of the EoS' we find that a new solution branch, which allows highly massive neutron stars, exists for values of α greater than a few 109 cm2. We find constraints on α for a variety of EoS' using the recent observational constraints on the mass-radius relation. These are all 5 orders of magnitude smaller than the recent constraint obtained via Gravity Probe B for this gravity model. The associated length scale cm is only an order of magnitude smaller than the typical radius of a neutron star, the probe used in this test. This implies that real deviations from general relativity can be even smaller.

Subfields: Astronomy and Astrophysics, Oceanography

View Paper: https://www.semanticscholar.org/paper/c87c3d7319921d45e58b159565a0196e836ded0b

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Citations in the corpus

Modified Gravity and Cosmology (2011, background): “Neutron stars in f(R) gravity have been studied in [332, 1099], and instabilities in systems with time-dependent mass have been studied in [60].”
Generalized Uncertainty Principle: Approaches and Applications (2014, unknown): “The QG effects are studied in various models [253–257, 259].”
New observational constraints on f(R) gravity from cosmic chronometers (2016, methodology): “In the case of f(R) gravity such a confrontation with cosmological data was performed in [48] (using data from cosmic microwave background (CMB) probes), in [49, 50] (using Large Scale Structure (LSS) data), in [51] (using neutron stars mass-radius data), in [52] (using Supernovae type Ia (SNe Ia) a”
Stellar structure models in modified theories of gravity: Lessons and challenges (2019, result): “This result seems to be in contradiction with the perturbative analysis of [213, 214, 219], where the positive α branch was reported to decrease the maximum mass.”