## Preferred frame parameters in the tensor-vector-scalar theory of gravity and its generalization

##### Date

##### Authors

Sagi, Eva

##### Journal Title

##### Journal ISSN

##### Volume Title

##### Publisher

##### Abstract

##### Description

The Tensor-Vector-Scalar theory of gravity, which was designed as a
relativistic implementation to the modified dynamics paradigm, has fared quite
well as an alternative to dark matter, on both galactic and cosmological
scales. However, its performance in the solar system, as embodied in the
post-Newtonian formalism, has not yet been fully investigated. Tamaki has
recently attempted to calculate the preferred frame parameters for TeVeS, but
ignored the cosmological value of the scalar field, thus concluding that the
Newtonian potential must be static in order to be consistent with the vector
equation. We show that when the cosmological value of the scalar field is taken
into account, there is no constraint on the Newtonian potential; however, the
cosmological value of the scalar field is tightly linked to the vector field
coupling constant K, preventing the former from evolving as predicted by its
equation of motion. We then proceed to investigate the post-Newtonian limit of
a generalized version of TeVeS, with {\AE}ther type vector action, and show
that its \beta,\gamma and \xi parameters are as in GR, while solar system
constraints on the preferred frame parameters \alpha_1 and \alpha_2 can be
satisfied within a modest range of small values of the scalar and vector fields
coupling parameters, and for values of the cosmological scalar field consistent
with evolution within the framework of existing models.

Comment: 16 pages, 2 figures Figures and corresponding discussion replaced; added references

Comment: 16 pages, 2 figures Figures and corresponding discussion replaced; added references

##### Keywords

General Relativity and Quantum Cosmology, Astrophysics - Astrophysics of Galaxies