We discuss the equivalence between a string theory and the two-dimensional Yang-Mills theory with SU(N) gauge group for finite N. We find a sector which can be interpreted as a sum of covering maps from closed string worldsheets to the target space, whose covering number is less than N. This gives an asymptotic expansion of 1/N whose large N limit becomes the chiral sector defined by Gross and Taylor. We also discuss that the residual part of the partition function provides the nonperturbative corrections to the perturbative expansion.
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Astronomy and Astrophysics
- Physics and Astronomy(all)