EXTENSION OF N = 2 SUPERCONFORMAL ALGEBRA AND CALABI-YAU COMPACTIFICATION

We study an extension of N = 2 superconformal algebra by the addition of the spectral flow generators. We present the extended algebra corresponding to complex 3-dimensional Calabi-Yau manifold and discuss its representation theory. We also discuss some symmetry properties of the non-linear σ model on the Ricci-flat Kahler manifold.