Work

Refining the MOND Interpolating Function and TeVeS Lagrangian

Year: 2006

Type: article

Abstract: The phenomena customarily described with dark matter or modified Newtonian dynamics (MOND) have been argued by Bekenstein to be the consequences of a covariant scalar field, controlled by a free function [related to the MOND interpolating function ( g / a 0 )] in its Lagrangian density. In the context of this relativistic MOND theory (TeVeS), we examine critically the interpolating function in the transition zone between weak and strong gravity. Bekenstein's toy model produces a that varies too gradually, and it fits rotation curves less well than the standard MOND interpolating function ( x ) = x /(1 + x 2 ) 1/2 . However, the latter varies too sharply and implies an implausible external field effect. These constraints on opposite sides have not yet excluded TeVeS, but they have made the zone of acceptable interpolating functions narrower. An acceptable "toy" Lagrangian density function with simple analytical properties is singled out for future studies of TeVeS in galaxies. We also suggest how to extend the model to solar system dynamics and cosmology.

Source: The Astrophysical Journal

DOI: 10.1086/500805

Authors: H. S. Zhao, B. Famaey

Institutions: University of St Andrews, Scottish Universities Physics Alliance, Particle Physics and Astronomy Research Council, Université Libre de Bruxelles, National Research Fund Luxembourg

Language: English

Topic: Cosmology and Gravitation Theories

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: bronze

Funder: Science and Technology Facilities Council

Award: G6176991832