1210.1010 (Yu-Huei Wu et al.)

Brans-Dicke theory of gravity with torsion: A possible solution of
$ω$-problem    [PDF]

Yu-Huei Wu, Chih-Hung Wang

We study Brans-Dicke theory of gravity in Riemann-Cartan space-times, and obtain general torsion solutions, which are completely determined by Brans-Dicke scalar field $\Phi$, in the false vacuum energy dominated epoch. The substitution of the torsion solutions back to our action gives the original Brans-Dicke action with $\Phi$-dependent Brans-Dicke parameter $\omega(\Phi)$. The evolution of $\omega(\Phi)$ during inflation is studied and it yields that $\omega$ approaches to infinity at the end of inflation. It may solve the $\omega$-problem in the extended inflation model.

View original: http://arxiv.org/abs/1210.1010