Abstract :
The four six-dimensional “little string” theories are all described in the infinite momentum frame (IMF) as matrix theories by non-trivial 1 + 1-dimensional infra-red fixed points. We characterize these fixed points using supergravity. Starting from the matrix theory definition of M5-branes, we derive an associated dual supergravity description of the fixed point theories, arising as the near-horizon geometry of certain brane configurations. These supergravity solutions are all smooth, and involve three-dimensional anti-de Sitter space AdS3. They therefore provide a complete description of the fixed point theories, and hence the IMF little string theories, if the AdS/CFT correspondence holds.
