In a variant of the Randall-Sundrum braneworld model which has a charged black hole in an anti-de Sitter bulk, the 4D speed of gravity depends upon one's location in the bulk, and in general differs from the speed of light on a given 3-brane. We apply phenomenological constraints on the difference in the speeds of light and gravity to models which use the warping to solve the hierarchy problem. In particular, consideration of the gravi-Cerenkov radiation of Kaluza-Klein gravitons by ultra-high energy cosmic rays, following the approach of Moore and Nelson, leads to a stringent limit on the fractional difference between the graviton and photon speeds in RS-like models: it must be less than a part in 1023.
Journal of High Energy Physics
- Pub Date:
- March 2004
- Field Theories in Higher Dimensions D-branes Black Holes High Energy Cosmic Rays;
- High Energy Physics - Phenomenology;
- High Energy Physics - Theory
- 17 pages, 5 figures