Journal of High Energy Physics (May 2019)
Multi-trace correlators from permutations as moduli space
Abstract
Abstract We study the n-point functions of scalar multi-trace operators in the U(N c ) gauge theory with adjacent scalars, such as N $$ \mathcal{N} $$ = 4 super Yang-Mills, at tree-level by using finite group methods. We derive a set of formulae of the general n-point functions, valid for general n and to all orders of 1/N c . In one formula, the sum over Feynman graphs becomes a topological partition function on Σ0,n with a discrete gauge group, which resembles closed string interactions. In another formula, a new skeleton reduction of Feynman graphs generates connected ribbon graphs, which resembles open string interaction. We define the moduli space ℳ g , n gauge $$ {\mathrm{\mathcal{M}}}_{g,n}^{\mathrm{gauge}} $$ from the space of skeleton-reduced graphs in the connected n-point function of gauge theory. This moduli space is a proper subset of ℳ g , n $$ {\mathrm{\mathcal{M}}}_{g,n} $$ stratified by the genus, and its top component gives a simple triangulation of Σ g,n .
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