ON THE DUALITY BETWEEN THE HETEROTIC STRING AND F-THEORY IN 8 DIMENSIONS

In this note we compare the moduli spaces of the heterotic string comp actified on a two-torus and F-theory compactified on an elliptic K3 su rface for the case of an unbroken E(8) x E(8) gauge group. The explici t map relating the deformation parameters alpha and beta of the F-theo ry K3 surface to the moduli T and U of the heterotic torus is found us ing the close relationship between the K3 discriminant and the discrim inant of the Calabi-Yau-threefold X(1,1,2,8,12)(24) in the limit of a large base P-1.