Résumé |
How exactly do large N QFTs reassemble themselves into perturbative string
theories? This talk will focus on an example which explicitly illustrates a
general program of how this can happen around a free field fixed point.
Specifically, we consider n-point correlators in the symmetric product orbifold
theory, dual to tensionless strings on AdS_3, in a Gross-Mende like limit of large
conformal dimensions. These correlators are given in terms of branched covering
maps which we can exactly solve for in this limit, via a map to a matrix model
with a logarithmic potential. The spectral curve encoding the matrix model
solution then naturally gives rise to an integral over the dual string moduli
space through a special (Strebel) parameterization of the latter. This is a
precise realisation of what was proposed as the underlying mechanism for gauge-
string duality in weakly coupled QFTS. Finally, the integrand on the moduli space
can be cast in a number of striking forms including an action given by (the
modulus of) the Schwarzian of the covering map. |