Keywords: depth; local cohomology; Serre subcategory; $ZD$-module
Summary: Let $R$ be a Noetherian ring, and $I$ and $J$ be two ideals of $R$. Let $S$ be a Serre subcategory of the category of $R$-modules satisfying the condition $C_I$ and $M$ be a $ZD$-module. As a generalization of the $S$-${\rm depth}(I, M)$ and ${\rm depth}(I, J, M)$, the $S$-${\rm depth}$ of $(I, J)$ on $M$ is defined as $S$-${\rm depth}(I, J, M)=\inf \{S$-${\rm depth}(\frak {a}, M) \colon \frak {a}\in \widetilde {\rm W}(I,J)\}$, and some properties of this concept are investigated. The relations between $S$-${\rm depth}(I, J, M)$ and $H^{i}_{I,J}(M)$ are studied, and it is proved that $S$-${\rm depth}(I, J, M)=\inf \{i \colon H^{i}_{I,J}(M)\notin S\}$, where $S$ is a Serre subcategory closed under taking injective hulls. Some conditions are provided that local cohomology modules with respect to a pair of ideals coincide with ordinary local cohomology modules under these conditions. Let ${\rm Supp}_R H^{i}_{I,J}(M)$ be a finite subset of ${\rm Max}(R)$ for all $i<t$, where $M$ is an arbitrary $R$-module and $t$ is an integer. It is shown that there are distinct maximal ideals $\frak m_1, \frak m_2,\ldots ,\frak m_k\in {\rm W}(I, J)$ such that $H^{i}_{I,J}(M)\cong H^{i}_{\frak m_1}(M)\oplus H^{i}_{\frak m_2}(M)\oplus \cdots \oplus H^{i}_{\frak m_k}(M)$ for all $i<t$.
[1] Aghapournahr, M., Ahmadi-Amoli, K., Sadeghi, M. Y.: The concept of $(I,J)$-Cohen-Macaulay modules. J. Algebr. Syst. 3 (2015), 1-10. DOI 10.22044/JAS.2015.482 | MR 3534204
[3] Asadollahi, M., Khashyarmanesh, K., Salarian, S.: A generalization of the cofiniteness problem in local cohomology modules. J. Aust. Math. Soc. 75 (2003), 313-324. DOI 10.1017/s1446788700008132 | MR 2015320 | Zbl 1096.13522
[5] Brodmann, M. P., Sharp, R. Y.: Local Cohomology: An Algebraic Introduction with Geometric Applications. Cambridge Studies in Advanced Mathematics 60. Cambridge University Press, Cambridge (1998). DOI 10.1017/CBO9780511629204 | MR 1613627 | Zbl 0903.13006
[13] Takahashi, R., Yoshino, Y., Yoshizawa, T.: Local cohomology based on a nonclosed support defined by a pair of ideals. J. Pure Appl. Algebra 213 (2009), 582-600. DOI 10.1016/j.jpaa.2008.09.008 | MR 2483839 | Zbl 1160.13013