Cosmological limits on brane-world disappearing dark matter

In the currently popular Randall-Sundrum model, the universe is described as a three-space (3-brane) embedded in a five-dimensional anti-de Sitter spacetime with a large (infinite) extra dimension. This concept is motivated by the D-brane solution found in ten-dimensional superstring theory and eleven dimensional M-theory/supergravity. This talk summarizes some possible observational consequences of such brane-world cosmology. For example, a new “dark radiation” term arises in the cosmic evolution equations which can affect the radiation dominated epoch. Moreover, matter may literally disappear into (or reemerge from) the extra dimension. This suggests a new interpretations for dark matter, dark energy and their evolution. Constraints on these possibilities arise from observations of high redshift supernovae, galaxy-clusters, X-ray gas in galactic clusters, and the cosmic microwave background. So far, all of the available constraints are consistent with (and may even slightly favor) this cosmology.