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arXiv · 1702.02983

Neutron Stars in Screened Modified Gravity: Chameleon vs Dilaton

Philippe Brax·Anne-Christine Davis·Rahul Jha
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Abstract

We consider the scalar field profile around relativistic compact objects such as neutron stars for a range of modified gravity models with screening mechanisms of the chameleon and Damour-Polyakov types. We focus primarily on inverse power law chameleons and the environmentally dependent dilaton as examples of both mechanisms. We discuss the modified Tolman-Oppenheimer-Volkoff equation and then implement a relaxation algorithm to solve for the scalar profiles numerically. We find that chameleons and dilatons behave in a similar manner and that there is a large degeneracy between the modified gravity parameters and the neutron star equation of state. This is exemplified by the modifications to the mass-radius relationship for a variety of model parameters.

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Philippe Brax, Anne-Christine Davis, Rahul Jha. 2017-02-09. Neutron Stars in Screened Modified Gravity: Chameleon vs Dilaton. https://doi.org/10.1103/physrevd.95.083514

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