Edoardo Ballico, Changho Keem

Quadric Hypersurfaces Containing a Projectively Normal Curve

Abstract:
Let $C \subset {\bf {P}}^n$ be a smooth projectively normal curve. Let $Z$ be the scheme-theoretic base locus of $H^0({\bf {P}}^n,\mathcal {I}_C(2))$ and $Z'$ the connected component of $Z$ containing $C$. Here we show that $Z'=C$ in certain cases (e.g., non-special line bundles with degree near to $2p_a(C)-2$ or certain special line bundles on general $k$-gonal curves).

Keywords:
Quadric hypersurfaces, $k$-gonal curves, gonality, projective normality, normally generated line bundle.

MSC 2000: 14H45, 14H50