Brane-World Gravity

摘要: The observable universe could be a 1+3-surface (the "brane") embedded in 1+3+d-dimensional spacetime "bulk"), with standard-model particles and fields trapped on the brane while gravity is free to access bulk. At least one of d extra spatial dimensions very large relative Planck scale, which lowers fundamental possibly even down electroweak (~ TeV) level. This revolutionary picture arises framework recent developments M theory. 1+10-dimensional theory encompasses known 1+9-dimensional superstring theories, widely considered promising potential route quantum gravity. General relativity cannot describe at high enough energies must replaced by theory, picking up significant corrections as energy scale approached. low energies, localized general recovered, but "leaks" into bulk, behaving truly way. introduces changes gravitational dynamics perturbations, interesting testable implications for high-energy astrophysics, black holes cosmology. Brane-world models offer phenomenological way test some novel predictions that are implied review discusses geometry, perturbations simple brane-world cosmology mainly focusing warped 5-dimensional brane-worlds based Randall-Sundrum models.