• 제목/요약/키워드: Cohen-macaulay ring

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LOCALLY COMPLETE INTERSECTION IDEALS IN COHEN-MACAULAY LOCAL RINGS

  • Kim, Mee-Kyoung
    • 대한수학회논문집
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    • 제9권2호
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    • pp.261-264
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    • 1994
  • Throughout this paper, all rings are assumed to be commutative with identity. By a local ring (R, m), we mean a Noetherian ring R which has the unique maximal ideal m. By dim(R) we always mean the Krull dimension of R. Let I be an ideal in a ring R and t an indeterminate over R. Then the Rees algebra R[It] is defined to be(omitted)

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EQUIMULTIPLE GOOD IDEALS WITH HEIGHT 1

  • Kim, Mee-Kyoung
    • 대한수학회지
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    • 제39권1호
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    • pp.127-135
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    • 2002
  • Let I be an ideal in a Gorenstein local ring A with the maximal ideal m. Then we say that I is an equimultiple good ideal in A, if I contains a reduction Q = ( $a_1$, $a_2$,ㆍㆍㆍ, $a_{s}$ ) generated by s elements in A and G(I) =(equation omitted)$_{n 0}$ $I^{n}$ / $I^{n+1}$ of I is a Gorenstein ring with a(G(I)) = 1 - s, where s = h $t_{A}$ I and a(G(I)) denotes the a-invariant of G(I). Let $X_{A}$$^{s}$ denote the set of equimultiple good ideals I in A with h $t_{A}$ I = s, R(I) = A [It] be the Rees algebra of I, and $K_{R(I)}$ denote the canonical module of R(I). Let a I such that $I^{n+l}$ = a $I^{n}$ for some n$\geq$0 and $\mu$$_{A}$(I)$\geq$2, where $\mu$$_{A}$(I) denotes the number of elements in a minimal system of generators of I. Assume that A/I is a Cohen-Macaulay ring. We show that the following conditions are equivalent. (1) $K_{R(I)}$(equation omitted)R(I)+as graded R(I)-modules. (2) $I^2$ = aI and aA : I$\in$ $X^1$$_{A}$._{A}$./.

ON THE κ-REGULAR SEQUENCES AND THE GENERALIZATION OF F-MODULES

  • Ahmadi-Amoli, Khadijeh;Sanaei, Navid
    • 대한수학회지
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    • 제49권5호
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    • pp.1083-1096
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    • 2012
  • For a given ideal I of a Noetherian ring R and an arbitrary integer ${\kappa}{\geq}-1$, we apply the concept of ${\kappa}$-regular sequences and the notion of ${\kappa}$-depth to give some results on modules called ${\kappa}$-Cohen Macaulay modules, which in local case, is exactly the ${\kappa}$-modules (as a generalization of f-modules). Meanwhile, we give an expression of local cohomology with respect to any ${\kappa}$-regular sequence in I, in a particular case. We prove that the dimension of homology modules of the Koszul complex with respect to any ${\kappa}$-regular sequence is at most ${\kappa}$. Therefore homology modules of the Koszul complex with respect to any filter regular sequence has finite length.

MINIMAL RESOLUTION CONJECTURES AND ITS APPLICATION

  • Cho, Young-Hyun
    • 대한수학회논문집
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    • 제13권2호
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    • pp.217-224
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    • 1998
  • In this paper we study the minimal resolution conjecture which is a generalization of the ideal generation conjecture. And we show how the results about this conjecture can make the calculation of minimal resolution in certain cases.

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ON THE FIRST GENERALIZED HILBERT COEFFICIENT AND DEPTH OF ASSOCIATED GRADED RINGS

  • Mafi, Amir;Naderi, Dler
    • 대한수학회보
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    • 제57권2호
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    • pp.407-417
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    • 2020
  • Let (R, m) be a d-dimensional Cohen-Macaulay local ring with infinite residue field. Let I be an ideal of R that has analytic spread ℓ(I) = d, satisfies the Gd condition, the weak Artin-Nagata property AN-d-2 and m is not an associated prime of R/I. In this paper, we show that if j1(I) = λ(I/J) + λ[R/(Jd-1 :RI+(Jd-2 :RI+I):R m)] + 1, then I has almost minimal j-multiplicity, G(I) is Cohen-Macaulay and rJ(I) is at most 2, where J = (x1, , xd) is a general minimal reduction of I and Ji = (x1, , xi). In addition, the last theorem is in the spirit of a result of Sally who has studied the depth of associated graded rings and minimal reductions for m-primary ideals.

BALANCE FOR RELATIVE HOMOLOGY WITH RESPECT TO SEMIDUALIZING MODULES

  • Di, Zhenxing;Zhang, Xiaoxiang;Chen, Jianlong
    • 대한수학회보
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    • 제52권1호
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    • pp.137-147
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    • 2015
  • We derive in the paper the tensor product functor -${\otimes}_R$- by using proper $\mathcal{GP}_C$-resolutions, where C is a semidualizing module. After giving several cases in which different relative homologies agree, we use the Pontryagin duals of $\mathcal{G}_C$-projective modules to establish a balance result for such relative homology over a Cohen-Macaulay ring with a dualizing module D.