Laurent coefficients and Ext of finite graded modules
Laurent coefficients and Ext of finite graded modules
复制标题
有限分级模的洛朗系数和 Ext
DOI：
10.1007/s002080050041
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发表时间：
1994
影响因子：
1.4
通讯作者：
J. Sally
中科院分区：
文献类型：
--
作者：
L. Avramov;R. Buchweitz;J. Sally
(N)目前的研究开始试图“解释”这个有趣的公式，并找出是否存在类似的等式，为后续的系数劳伦膨胀约1。相当完整的答案在第3节和第4节中给出。它们依赖于将（1）嵌入到洛朗级数的等式中，该等式“预测”了高洛朗系数之间相似关系的无穷序列。结果在第1节中得到证明，并在第2节中用于获得某些有限内射维度分次模的Bass数的非平凡下界。
(N)ψ(M).The present investigation started as an attempt to “explain” this intriguing formula,and to find out whether analogous equalities exist for subsequent coefficients of Laurentexpansions around 1. Fairly complete answers are presented in Sections 3 and 4. Theydepend on embedding (1) into an equality of Laurent series, which “predicts” an infinitesequence of similar relations among higher Laurent coefficients. The results are proved inSection 1, and are used in Section 2 to obtain non-trivial lower bounds for the Bass numbersof certain graded modules of finite injective dimension.