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Title: Modified gravity inside astrophysical bodies

Many theories of modified gravity, including the well studied Horndeski models, are characterized by a screening mechanism that ensures that standard gravity is recovered near astrophysical bodies. In a recently introduced class of gravitational theories that goes beyond Horndeski, it has been found that new derivative interactions lead to a partial breaking of the Vainshtein screening mechanism inside any gravitational source, although not outside. We study the impact of this new type of deviation from standard gravity on the density profile of a spherically symmetric matter distribution, in the nonrelativistic limit. For simplicity, we consider a polytropic equation of state and derive the modifications to the standard Lane-Emden equations. We also show the existence of a universal upper bound on the amplitude of this type of modified gravity, independently of the details of the equation of state.
Authors:
;  [1] ;  [2] ;  [3] ;  [4]
  1. AstroParticule et Cosmologie, CNRS-Universite Paris 7, 10 rue Alice Domon et Léonie Duquet, Paris (France)
  2. Research Center for the Early Universe, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo (Japan)
  3. Waseda Institute for Advanced Study, Waseda University, 1-6-1 Nishi-Waseda Shinjuku-ku, Tokyo (Japan)
  4. Institut de Physique Théorique, CEA, Gif-sur-Yvette (France)
Publication Date:
OSTI Identifier:
22525787
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2015; Journal Issue: 06; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; AMPLITUDES; ASTROPHYSICS; COSMOLOGICAL MODELS; EQUATIONS OF STATE; GRAVITATION; MODIFICATIONS; SPHERICAL CONFIGURATION; SYMMETRY