Multitrace deformations and their holographic duals

by Eliezer Rabinovici / Hebrew Univ. Jerusalem

Tuesday 7 Feb 2006, 14:00 → 15:00 Europe/Zurich

TH Auditorium (CERN)

We study the effect of multitrace deformations in conformal theories admitting holographic duals in Anti-de Sitter space. In particular, we analyse the case that these deformations introduce an instability both in the bulk AdS space and in the boundary CFT. We also argue that multitrace deformations of the O(N) linear sigma model in three dimensions correspond to non-trivial time-dependent backgrounds in certain theories of infinitely many interacting massless fields on AdS₄, proposed years ago by Fradkin and Vasiliev. We point out that the phase diagram of a truly marginal large-N deformation has an infra-red limit in which only an O(N) singlet field survives. We draw from this case lessons on the full string-theoretical interpretation of instabilities of the dual boundary theory and their diagnostic value for testing possible resolutions of space like singularities in string theory. We exhibit a toy model that resolves the instability of the O(N) model, generated by a marginal multitrace deformation. The resolution suggests that the instability may not survive in an appropriate UV completion of the CFT.