1209.2892 (B. Hoare et al.)

Pohlmeyer reduction for superstrings in AdS space    [PDF]

B. Hoare, A. A. Tseytlin

The Pohlmeyer reduced equations for strings moving only in the AdS subspace of AdS_5 x S^5 have been used recently in the study of classical Euclidean minimal surfaces for Wilson loops and some semiclassical three-point correlation functions. We find an action that leads to these reduced superstring equations. For example, for a bosonic string in AdS_n such an action contains a Liouville scalar part plus a K/K gauged WZW model for the group K=SO(n-2) coupled to another term depending on two additional fields transforming as vectors under K. For n=5 we generalize this bosonic action to include the S^5 contribution and fermionic terms. Our construction is based on taking a limit of the previously found reduced theory actions for bosonic strings in AdS_n x S^1 and superstrings in AdS_5 x S^5. This new action may be useful as a starting point for possible quantum generalizations or deformations of the classical Pohlmeyer-reduced theory. We give examples of simple extrema of this reduced superstring action which represent strings moving in the AdS_5 part of the space. Expanding near these backgrounds we compute the corresponding fluctuation spectra and show that they match the spectra found in the original superstring theory.

View original: http://arxiv.org/abs/1209.2892