# Large-N factorization of single-trace operators

Does anyone know where I can find a pedagogical explanation of large-N factorization in SU(N) gauge theories or nonlinear O(N) sigma models (in the latter case the trace corresponds to a dot product).

The reference I am using is Polyakov's gauge fields and strings. However, I find the explanation of large-N factorization there quite opaque.

Thanks.

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I would look at Coleman's lecture in his book "Aspects of Symmetry" or arxiv.org/abs/hep-th/0306133 –  David Meltzer Jan 4 '14 at 5:55