Noncommutative U(1) Gauge Theory As a Non-Linear Sigma Model

Noncommutative U(1) gauge theory in 4-dimensions is shown to be equivalent in some scaling limit to an ordinary non-linear sigma model in 2-dimensions . The model in this regime is solvable and the corresponding exact beta function is found. We also show that classical U(n) gauge theory on {R}^{d-2}{\times}{R}^2_{\theta} can be approximated by a sequence of ordinary (d-2)-dimensional Georgi-Glashow models with gauge groups U(n(L+1)) where L+1 is the matrix size of the regularized noncommutative plane {R}^2_{\theta}.