We develop techniques to study the correlation functions of "large operators" whose bare dimension grows parametrically with N, in SO(N) gauge theory. We build the operators from a single complex matrix. For these operators, the large N limit of correlation functions is not captured by summing only the planar diagrams. By employing group representation theory we are able to define local operators which generalize the Schur polynomials of the theory with gauge group U(N). We compute the two point function of our operators exactly in the free field limit showing that they diagonalize the two point function. We explain how these results can be used to obtain the exact free field answers for correlators of operators in the trace basis.

Using the recently constructed basis for local operators in free SO(N) gauge theory we derive an exact formula for the correlation functions of multi trace operators. This formula is used to obtain a simpler form and a simple product rule for the operators in the SO(N) basis. The coefficients of the product rule are the Littlewood-Richardson numbers which determine the corresponding product rule in free U(N) gauge theory. SO(N) gauge theory is dual to a non-oriented string theory on the AdS 5 ×RP 5 geometry. To explore the physics of this string theory we consider the limit of the gauge theory that, for the U(N) gauge theory, is dual to the pp-wave limit of AdS 5 × S 5 . Non-planar unoriented ribbon diagrams do not survive this limit. We give arguments that the number of operators in our basis matches counting using the exact free field partition function of free SO(N) gauge theory. We connect the basis we have constructed to free fermions, which has a natural interpretation in terms of a class of

We define restricted Schur polynomials built using both fermionic and bosonic fields which transform in the adjoint of the gauge group U(N). We show that these operators diagonalize the free field two point function to all orders in 1/N. As an application of our new operators, we study the action of the one loop dilatation operator in the su(2|3) sector in a large N but non-planar limit. The restricted Schur polynomials we study are dual to giant gravitons. We find that the one loop dilatation operator can be diagonalized using a double coset ansatz. The resulting spectrum of anomalous dimensions matches the spectrum of a set of decoupled oscillators. Finally, in an Appendix we study the action of the one loop dilatation operator in an sl(2) sector. This action is again diagonalized by a double coset ansatz.

In this paper we construct two infinite sets of self-adjoint commuting charges for a quite general CFT. They come out naturally by considering an infinite embedding chain of Lie algebras, an underlying structure that share all theories with gauge groups U (N ), SO(N ) and Sp(N ). The generality of the construction allows us to carry all gauge groups at the same time in a unified framework, and so to understand the similarities among them. The eigenstates of these charges are restricted Schur polynomials and their eigenvalues encode the value of the correlators of two restricted Schurs. The existence of these charges singles out restricted Schur polynomials among the number of bases of orthogonal gauge invariant operators that are available in the literature.

Representation theory provides an efficient framework to count and classify invariants in tensor models of (gauge) symmetryWe show that there are two natural ways of counting invariants, one for arbitrary G d and another valid for large rank of G d . We construct basis of invariant operators based on the counting, and compute correlators of their elements. The basis associated with finite rank of G d diagonalizes two-point function. It is analogous to the restricted Schur basis used in matrix models. We comment on future directions for investigation.