  We take a step toward a "microscopic" derivation of gauge-string duality. In
particular, using mathematical techniques of Strebel differentials and discrete
exterior calculus, we obtain a bosonic string worldsheet action for a string
embedded in d+1 dimensional asymptotically AdS space from multi-loop Feynman
graphs of a quantum field theory of scalar matrices in d-dimensions in the
limit of diverging loop number. Our work is building on the program started by
't Hooft in 1974, this time including the holographic dimension which we show
to emerge from the continuum of Schwinger parameters of Feynman diagrams.
