An gravitation for galactic environments
Institute for Advanced Studies in Basic Sciences, PO B 45195-1159, Zanjan, Iran e-mail: firstname.lastname@example.org
Accepted: 13 December 2006
We propose an action-based modification of Einstein's gravity that admits a modified Schwarzschild-deSitter metric. In the weak field limit this amounts to adding a small logarithmic correction to the Newtonian potential. A test star moving in such a spacetime acquires a constant asymptotic speed at large distances. This speed, calibrated empirically, is proportional to the fourth root of the mass of the central body in compliance with the Tully-Fisher relation. A variance of MOND's gravity emerges as an inevitable consequence of the proposed formalism. It has also been shown (Mendoza et al. [CITE], [arXiv:astroph/0610390]) that a) the gravitational waves in this spacetime propagate with the speed of light in vacuum and b) there is a lensing effect added to what one finds in the classic GR.
Key words: cosmology: theory / cosmology: dark matter / gravitation / galaxies: photometry
© ESO, 2007