On the cosmology of scalar-tensor-vector gravity theory

We consider the cosmological consequences of a special scalar-tensor-vector theory of gravity, known as MOG in the literature, proposed to address the dark matter problem. This theory introduces two scalar fields $G(x)$ and $\mu(x)$, and one vector field $\phi_{\alpha}(x)$, in addition to the metric...

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Bibliographic Details
Main Authors: Jamali, Sara (Author) , Roshan, Mahmood (Author) , Amendola, Luca (Author)
Format: Article (Journal) Chapter/Article
Language:English
Published: 10 Jul 2017
In: Arxiv

Online Access:Verlag, kostenfrei, Volltext: http://arxiv.org/abs/1707.02841
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Author Notes:Sara Jamali, Mahmood Roshan and Luca Amendola
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Summary:We consider the cosmological consequences of a special scalar-tensor-vector theory of gravity, known as MOG in the literature, proposed to address the dark matter problem. This theory introduces two scalar fields $G(x)$ and $\mu(x)$, and one vector field $\phi_{\alpha}(x)$, in addition to the metric tensor. We set the corresponding self-interaction potentials to zero, as in the standard form of MOG. Then using the phase space analysis in the flat Friedmann-Robertson-Walker background, we show that the theory possesses a viable sequence of cosmological epochs with acceptable time dependency for the cosmic scale factor. We also investigate MOG's potential as a dark energy model and show that extra fields in MOG can not provide a late time accelerated expansion. Furthermore, using a dynamical system approach to solve the non-linear field equations numerically, we calculate the angular size of the sound horizon, i.e. $\theta_{\text{s}}$, in MOG. We find that $8\times 10^{-3}\text{rad}<\theta_{\text{s}}<8.2\times 10^{-3} \text{rad} $ which is way outside the current observational bounds. Finally we generalize MOG to find a model that passes the sound-horizon constraint and might produce a viable version of MOG.
Item Description:Gesehen am 19.10.2017
Physical Description:Online Resource