Living Reviews in RelativityCurrent articles from Living Reviews in Relativity. Living Reviews in Relativity is a peer-refereed, solely online physics journal publishing invited reviews covering all areas of relativity research. Reviews are kept up to date by their authors. All reference information is collected into a searchable database. Living Reviews in Relativity is a free resource to the scientific community. Published by the Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Potsdam,...Spacelike Singularities and Hidden Symmetries of Gravity- April 24, 2008 We review the intimate connection between (super-)gravity close to a spacelike singularity (the BKL-limit) and the theory of Lorentzian Kac-Moody algebras. We show that in this limit the gravitational theory can be reformulated in terms of billiard motion in a region of hyperbolic space, revealing that the dynamics is completely determined by a (possibly infinite) sequence of reflections, which are elements of a Lorentzian Coxeter group. Such Coxeter groups are the Weyl groups of...http://www.livingreviews.org/lrr-2008-1 |