Normal Presentation on Elliptic Ruled Surfaces
نویسنده
چکیده
are surjective for all m ≥ 2. If L is normally generated, then we say that L satisfies property Np, if the matrices in the free resolution of R over S have linear entries until the pth stage. In particular, property N1 says that the homogeneous ideal I of X in P(H(L)) is generated by quadrics. A line bundle satisfying property N1 is also called normally presented. Let R = k⊕R1 ⊕R2 ⊕ . . . be a graded algebra over a field k. The algebra R is a Koszul ring iff Tori (k,k) has pure degree i for all i.
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تاریخ انتشار 1995