Gauge theories as string theories: the first results
The gauge/string theory duality in curved space is
discussed mainly using a non-Abelian conformal N = 4 supersymmetric gauge theory and the theory of a closed superstring in the AdS5 x S5 metric as an example. It is shown that in the supergravity approximation, string duality yields the characteristics of a strong-coupling gauge theory. For a special shape of
the contour, a Wilson loop expression is derived in the classical
superstring approximation. The role of the hidden integrability
in lower-loop calculations in gauge theory and in different
approximations of string theory is discussed. It is demonstrated that in the large quantum-number limit, gauge theory operators can be described in terms of the dual string picture.
Examples of metrics providing the dual description of gauge
theories with broken conformal symmetry are presented, and
formulations of the vacuum structure of such theories in terms
of gravity are discussed.