Let X be a Gorenstein minimal projective 3-fold with at worst locally factorial terminal singularities. Suppose the canonical map is of fiber type. Denote by F a smooth model of a generic irreducible element in fibers of phi(1), and so F is a curve or a smooth surface. The main result is that there is a computable constant K independent of X such that g(F) less than or equal to 647 or p(g)(F) less than or equal to 38 whenever p(g)(X) greater than or equal to K.
机构:
Fudan Univ, Sch Math Sci, Shanghai 200433, Peoples R China
Fudan Univ, Shanghai Ctr Math Sci, Shanghai 200433, Peoples R ChinaFudan Univ, Sch Math Sci, Shanghai 200433, Peoples R China
机构:
Univ Calif Los Angeles, Dept Math, 520 Portola Plaza,Math Sci Bldg 6363, Los Angeles, CA 90024 USAUniv Calif Los Angeles, Dept Math, 520 Portola Plaza,Math Sci Bldg 6363, Los Angeles, CA 90024 USA