**Holography, Unfolding and Higher-Spin Theory**

Abstract:

Holographic duality is argued to relate classes of models
that have equivalent unfolded formulation, hence exhibiting
different space-time visualizations for the same theory. This
general phenomenon is illustrated by the AdS_4 higher-spin gauge
theory shown to be dual to the theory of 3d conformal currents of
all spins interacting with 3d conformal higher-spin fields of
Chern-Simons type. The resulting 3d boundary conformal theory is
nonlinear, providing an interacting version of the 3d boundary
sigma model conjectured by Klebanov and Polyakov to be dual to the
AdS_4 HS theory in the large N limit. Higher-spin holographic
duality will be also discussed for the AdS_3/CFT_2 case and
duality between higher-spin theories and nonrelativistic quantum
mechanics.