
Published online by Cambridge University Press: 22 January 2016
Our setting for this paper is projective 3-space  over an algebraically closed field K. By a curve C ⊂
 over an algebraically closed field K. By a curve C ⊂  is meant a 1-dimensional, equidimensional projective algebraic set, which is locally Cohen-Macaulay. Let
 is meant a 1-dimensional, equidimensional projective algebraic set, which is locally Cohen-Macaulay. Let  
  be the Hartshorne-Rao module of finite length (cf. [R]). Here Z is the set of integers and ℐc  the ideal sheaf of C. In [GMV] it is shown that
 be the Hartshorne-Rao module of finite length (cf. [R]). Here Z is the set of integers and ℐc  the ideal sheaf of C. In [GMV] it is shown that  , where
, where  is the homogeneous ideal of C,
 is the homogeneous ideal of C,  is the first local cohomology module of the R-module M with respect to
 is the first local cohomology module of the R-module M with respect to . Thus there exists a smallest nonnegative integer k ∊ N such that 
 , (see also the discussion on the 1-st local cohomology module in [GW]). Also in [GMV] it is shown that k = 0 if and only if C is arithmetically Cohen-Macaulay and C is arithmetically Buchsbaum if and only if k ≤ 1. We therefore have the following natural definition.
, (see also the discussion on the 1-st local cohomology module in [GW]). Also in [GMV] it is shown that k = 0 if and only if C is arithmetically Cohen-Macaulay and C is arithmetically Buchsbaum if and only if k ≤ 1. We therefore have the following natural definition.
 , Linear Alg. and Appl., 59 (1984), 121–129.Google Scholar
, Linear Alg. and Appl., 59 (1984), 121–129.Google Scholar