Talk abstract details

We investigate in detail two physical properties of the metric f(R) theory developed by Sobouti (2007) which accounts for different galactic phenomena. We first look for the possibility of producing gravitational waves that travel at the speed of light. We then check the possibility of producing extra bending in the lenses produced by the theory. We do this by using standard weak field approximations to the gravitational field equations that appear in Sobouti's theory. We show in general terms that for all metric theories of gravity which can be expressed as powers of Ricci's scalar, gravitational waves can travel at the speed of light in vacuum. We also show that an extra additional lensing as compared to the one predicted by standard general relativity is produced. These two points are generally considered to be of crucial importance in the development of relativistic theories of gravity that could provide an alternative description to the dark matter paradigm.