Matrix model , Kutasov duality and Factorization of Seiberg - Witten Curves ∗

We study the duality of N = 1 gauge theories in the presence of a massless adjoint field. We calculate the superpotential using the factorization method and compare with the result obtained by applying Kutasov duality. The latter result is just the leading term of the former, indicating that Kutasov duality is exact only in the IR limit as claimed in the original literature. We also study various checks for the equivalence of the calculational methods developed recently: factorization methods, diagrammatic expansion, loop equations, integrating fluxes. ∗Work supported partially by the Department of Energy under contract number DE-AC03-76SF005515 and by the Deutsche Forschungsgemeinschaft.