Worldsheet Form Factors in AdS/CFT
Thomas Klose, Tristan McLoughlin
TL;DR
<3-5 sentence high-level summary>We formulate a bootstrap-like set of form-factor axioms for the massive, integrable, non-relativistic AdS$_5\times$S$^5$ worldsheet theory and verify them perturbatively in the near-plane-wave and near-flat limits. The work then connects these worldsheet form factors to weakly coupled spin-chain observables, showing that the axioms hold on the gauge side and that, at leading order in small momentum, the string results reproduce the spin-chain thermodynamic limit. A non-linear map between worldsheet and spin-chain operators is required for off-shell matching, and the perturbative checks illustrate a consistent interpolation between strong and weak coupling. These results lay groundwork for solving the axioms exactly and for exploring holographic correlations via off-shell string observables.
Abstract
We formulate a set of consistency conditions appropriate to worldsheet form factors in the massive, integrable but non-relativistic, light-cone gauge fixed AdS(5) x S**5 string theory. We then perturbatively verify that these conditions hold, at tree level in the near-plane-wave limit and to one loop in the near-flat (Maldacena-Swanson) limit, for a number of specific cases. We further study the form factors in the weakly coupled dual description, verifying that the relevant conditions naturally hold for the one-loop Heisenberg spin-chain. Finally, we note that the near-plane-wave expressions for the form factors, when further expanded in small momentum or, equivalently, large charge density, reproduce the thermodynamic limit of the spin-chain results at leading order.
