We study the construction of new multiplication modules relative to a torsion theory $\tau$. As a consequence, $\tau$-finitely generated modules over a Dedekind domain are completely determined. We relate the relative multiplication modules to the distributive ones.

Let $R$ be a commutative Noetherian ring, and let $C$ be a semidualizing $R$-module. The notion of $C$-tilting $R$-modules is introduced as the relative setting of the notion of tilting $R$-modules with respect to $C$. Some properties of tilting and $C$-tilting modules and the relations between them are mentioned. It is shown that every finitely generated $C$-tilting $R$-module is $C$-projective. Finally, we investigate some kernel subcategories related to $C$-tilting modules.

The rational homology groups of packing complexes are important in algebraic geometry since they control the syzygies of line bundles on projective embeddings of products of projective spaces (Segre–Veronese varieties). These complexes are a common generalization of the multidimensional chessboard complexes and of the matching complexes of complete uniform hypergraphs, whose study has been a topic of interest in combinatorial topology. We prove that the multivariate version of representation stability,...

On considère l’espace de modules $M(c_1,c_2)$ des fibrés stables de rang $2$ sur ${\mathbb{P}}_k^3$, de classes de Chern $c_1,c_2$, $k$ étant un corps algébriquement clos de caractéristique quelconque. Si ($c_1=0,c_2\>0$) ou ($c_1=-1,c_2=2p\ge 6$), on sait ([7], [9]) que $M(c_1,c_2)$ a une composante irréductible dont le point générique $ℱ(c_1,c_2)$ a la cohomologie naturelle. Nous avons calculé ([16]) la résolution minimale de $ℱ(0,c_2)$. Dans cet article, nous voulons déterminer celle de $ℱ(-1,c_2)$ si ${\displaystyle c_2\>\frac{(v+2)(2v^2+3v-1)}{6v+7},}$ où $v$ est le plus petit entier tel que $h^0\left(ℱ\left(v\right)\right)\>0$. Par un procédé standard rappelé dans [16], on se ramène à des...

We define and study restricted projective, injective and flat dimensions over local homomorphisms. Some known results are generalized. As applications, we show that (almost) Cohen-Macaulay rings can be characterized by restricted homological dimensions over local homomorphisms.

This paper deals with the rings which satisfy $DC{C}_d$ condition. This notion has been introduced recently by R. Dastanpour and A. Ghorbani (2017) as a generalization of Artnian rings. It is of interest to investigate more deeply this class of rings. This study focuses on commutative case. In this vein, we present this work in which we examine the transfer of these rings to the trivial, amalgamation and polynomial ring extensions. We also investigate the relationship between this class of rings and the...

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 $S$-$\mathrm{depth}(I,M)$ and $\mathrm{depth}(I,J,M)$, the $S$-$\mathrm{depth}$ of $(I,J)$ on $M$ is defined as $S$-$\mathrm{depth}(I,J,M)=inf\{S$-$\mathrm{depth}(𝔞,M):𝔞\in \tilde{\mathrm{W}}(I,J)\}$, and some properties of this concept are investigated. The relations between $S$-$\mathrm{depth}(I,J,M)$ and $H_{I,J}^i\left(M\right)$ are studied, and it is proved that $S$-$\mathrm{depth}(I,J,M)=inf\{i:H_{I,J}^i\left(M\right)\notin S\}$, where $S$ is a Serre subcategory closed under taking injective hulls. Some conditions are provided that local cohomology modules with...

In this paper we compute the dimension of all the sth higher secant varieties of the Segre-Veronese embeddings Yd of the product P1 × P1 × P1 in the projective space PN via divisors of multidegree d = (a,b,c) (N = (a+1)(b+1)(c+1) - 1). We find that Yd has no deficient higher secant varieties, unless d = (2,2,2) and s = 7, or d = (2h,1,1) and s = 2h + 1, with defect 1 in both cases.