Dynamical masses in modified gravity

Journal Article · Sat May 15 04:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.103002· OSTI ID:21409686

Schmidt, Fabian ^[1]

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1. Theoretical Astrophysics, California Institute of Technology M/C 350-17, Pasadena, California 91125-0001 (United States)

Differences in masses inferred from dynamics, such as velocity dispersions or x rays, and those inferred from lensing are a generic prediction of modified gravity theories. Viable models, however, must include some nonlinear mechanism to restore general relativity (GR) in dense environments, which is necessary to pass Solar System constraints on precisely these deviations. In this paper, we study the dynamics within virialized structures in the context of two modified gravity models, f(R) gravity and Dvali-Gabadadze-Porrati (DGP). The nonlinear mechanisms to restore GR, which f(R) and DGP implement in very different ways, have a strong impact on the dynamics in bound objects; they leave distinctive signatures in the dynamical mass-lensing mass relation as a function of mass and radius. We present measurements from N-body simulations of f(R) and DGP, as well as semianalytical models that match the simulation results to surprising accuracy in both cases. The semianalytical models are useful for making the connection to observations. Our results confirm that the environment and scale dependence of the modified gravity effects have to be taken into account when confronting gravity theories with observations of dynamics in galaxies and clusters.

• OSTI ID: 21409686
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 10 Vol. 81; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
DISPERSIONS
ELECTROMAGNETIC RADIATION
FIELD THEORIES
FORECASTING
GALAXIES
GENERAL RELATIVITY THEORY
GRAVITATION
IONIZING RADIATIONS
MASS
NONLINEAR PROBLEMS
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RELATIVITY THEORY
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