Let G be a hyper finite locally solvable group, A a minimax ZG-medule, a locally defined formation consisting of locally solvable groups, A has no nonzero infinite irreducible ZG-factors, and G ∈ . The following resu...Let G be a hyper finite locally solvable group, A a minimax ZG-medule, a locally defined formation consisting of locally solvable groups, A has no nonzero infinite irreducible ZG-factors, and G ∈ . The following results are proved: if A has a maximal submodule B such that A/B is , central in G and B has no nonzero central ZG-factors, then A has an decomposition; ifA has an irreducible central submodule B such that all ZG-composition factors of A/B are o^eccentric, then A has an decomposition.展开更多
Let (R, m) be a commutative Noetherian local ring, I an ideal of R and M a finitely generated R-module. Let limnHm^i(M/I^nM)be the ith formal local cohomology module of M with respect to I.In this paper, we discus...Let (R, m) be a commutative Noetherian local ring, I an ideal of R and M a finitely generated R-module. Let limnHm^i(M/I^nM)be the ith formal local cohomology module of M with respect to I.In this paper, we discuss some properties of formal local cohomology modules limnHm^i(M/I^nM),which are analogous to the finiteness and Artinianness of local cohomology modules of a finitely generated module.展开更多
Let M be a non-zero finitely generated module over a commutative Noetherian local ring (R, m). In this paper we consider when the local cohomology modules are finitely generated. It is shown that if t≥ 0 is an inte...Let M be a non-zero finitely generated module over a commutative Noetherian local ring (R, m). In this paper we consider when the local cohomology modules are finitely generated. It is shown that if t≥ 0 is an integer and p C Supp H^t_p (M), then Hm^t+dim R/p (M) is not p-cofinite. Then we obtain a partial answer to a question raised by Huneke. Namely, if R is a complete local ring, then H^n_m (M) is finitely generated if and only if 0 ≤ n ¢ W, where W ---- {t + dimR/p丨p ∈ SuppH^t_p(M)/V(m)}. Also, we show that if J C I are 1-dimensional ideals of R, then H^t_I(M) is J-cominimax, and H^t_I(M) is finitely generated (resp., minimax) if and only if H}R, (Mp) is finitely generated for all p C Spec R (resp., p ∈ SpecR/MaxR). Moreover, the concept of the J-cofiniteness dimension cJ(M) of M relative to I is introduced, and we explore an interrelation between c^I_m(M) and the filter depth of M in I. Finally, we show that if R is complete and dim M/IM ≠ 0, then c^I_m (R) ---- inf{depth Mp + dim R/p 丨 P ∈ Supp M/IM/V(m)}.展开更多
文摘Let G be a hyper finite locally solvable group, A a minimax ZG-medule, a locally defined formation consisting of locally solvable groups, A has no nonzero infinite irreducible ZG-factors, and G ∈ . The following results are proved: if A has a maximal submodule B such that A/B is , central in G and B has no nonzero central ZG-factors, then A has an decomposition; ifA has an irreducible central submodule B such that all ZG-composition factors of A/B are o^eccentric, then A has an decomposition.
基金The NSF (10771152,10926094) of Chinathe NSF (09KJB110006) for Colleges and Universities in Jiangsu Provincethe Research Foundation (Q4107805) of Soochow University and the Research Foundation (Q3107852) of Pre-research Project of Soochow University
文摘Let (R, m) be a commutative Noetherian local ring, I an ideal of R and M a finitely generated R-module. Let limnHm^i(M/I^nM)be the ith formal local cohomology module of M with respect to I.In this paper, we discuss some properties of formal local cohomology modules limnHm^i(M/I^nM),which are analogous to the finiteness and Artinianness of local cohomology modules of a finitely generated module.
文摘Let M be a non-zero finitely generated module over a commutative Noetherian local ring (R, m). In this paper we consider when the local cohomology modules are finitely generated. It is shown that if t≥ 0 is an integer and p C Supp H^t_p (M), then Hm^t+dim R/p (M) is not p-cofinite. Then we obtain a partial answer to a question raised by Huneke. Namely, if R is a complete local ring, then H^n_m (M) is finitely generated if and only if 0 ≤ n ¢ W, where W ---- {t + dimR/p丨p ∈ SuppH^t_p(M)/V(m)}. Also, we show that if J C I are 1-dimensional ideals of R, then H^t_I(M) is J-cominimax, and H^t_I(M) is finitely generated (resp., minimax) if and only if H}R, (Mp) is finitely generated for all p C Spec R (resp., p ∈ SpecR/MaxR). Moreover, the concept of the J-cofiniteness dimension cJ(M) of M relative to I is introduced, and we explore an interrelation between c^I_m(M) and the filter depth of M in I. Finally, we show that if R is complete and dim M/IM ≠ 0, then c^I_m (R) ---- inf{depth Mp + dim R/p 丨 P ∈ Supp M/IM/V(m)}.