We consider the infrared modification of gravity by the ghost condensate. Naively, in this scenario one expects sizable modification of gravity at distances of order 1000 km, provided that the characteristic timescale of the theory is of the order of the Hubble time. However, we argue that this is not the case. The main physical reason for the masking is the simple fact that the Earth (and any other object in the Universe) has a velocity at least of order 10-3c with respect to the rest frame of the ghost condensate. Taken together with strong retardation effects present in the ghost sector, this implies that no observable modification of the gravitational field of nearby objects occurs. Instead, the physical manifestation of the ghost condensate is the presence of 'star tracks' -narrow regions of space with growing gravitational and ghost fields inside - along the trajectory of any massive object. We briefly discuss the possibilities for observing these tracks.
|Original language||English (US)|
|Number of pages||17|
|Journal||Journal of Cosmology and Astroparticle Physics|
|State||Published - Jul 2004|
- Dark energy theory
ASJC Scopus subject areas
- Astronomy and Astrophysics