Large N field theory of N=2 strings and self-dual gravity

We review some aspects of the construction of self-dual gravity and the ass ociated field theory of N = 2 strings in terms of two-dimensional sigma mod els at large N. The theory is defined through a large N Wess-Zumino-Witten model in a nontrivial background and in a particular double scaling limit. We examine the canonical structure of the theory and describe an infinite-d imensional Poisson algebra of currents. (C) 1999 Elsevier Science Ltd. All rights reserved.