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arXiv 2601.20596math.AC
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Ext的 annihilator

Annihilator of $Ext^g_R(R/I,R)$

Mohsen Asgharzadeh

AI总结:

本文研究了Ext的 annihilator 的结构和性质,探讨了其在不同理想类中的包含关系,并给出了相关应用。

摘要:

我们研究了与理想I的等级g相关的更高除数理想D(I):= Ann(Ext^g_R(R/I,R))。我们的主要关注点是包含问题D(I) ⊆ \overline{I}。我们证明,对于广泛的理想类,包括有限射影维数的unmixed理想、准正则环上的参数理想,以及在合适同调条件下完美理想幂,这种包含关系成立。相反,我们构造了显式的例子,证明这些假设的必要性。我们开发了D(I)的结构性质,将其与unmixed部分、反射闭包、符号幂、Frobenius闭包和迹理想相关联。应用包括反射模和 punctured spectra 上向量包的平凡性准则,以及 annihilators of Ext、导出理想和局部上同调之间的新联系。

英文摘要:

We investigate the higher divisorial ideal $D(I) := Ann(Ext^g_R(R/I,R))$ associated to an ideal $I$ of grade $g$. Our main focus is the containment problem $ D(I) \subseteq \overline{I}$. We show that this inclusion holds for broad classes of ideals, including unmixed ideals of finite projective dimension over $3$-dimensional quasi-normal rings, parameter ideals in quasi-Gorenstein rings, and powers of perfect ideals under suitable homological conditions. If $R$ is Cohen--Macaulay local, $I$ is height-unmixed, and suppose $pdim_R(R/I)<\infty$, then we show $ D_R(I)=I\subseteq \overline{I}.$ Conversely, we construct explicit examples demonstrating the necessity of these hypotheses. We develop structural properties of $D(I)$, relating it to unmixed parts, reflexive closures, symbolic powers, Frobenius closure, and trace ideals. Applications include the rigidity property of homological annihilators, a criteria for the triviality of reflexive modules and vector bundles on punctured spectra, as well as new connections among annihilators of Ext, conductor ideals, and local cohomology.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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