Some cases of a conjecture on L-functions of twisted Carlitz modules

We prove two polynomial identies which are particular cases of a conjecture arising in the theory of L-functions of twisted Carlitz modules. This conjecture is stated in [6 Grishkov, A., Logachev, D. (2016). Resultantal varieties related to zeroes of L-functions of Carlitz modules. Finite Fields Appl. 38:116–176. Available at: arxiv.org/pdf/1205.2900.pdf.[Crossref], [Web of Science ®] , [Google Scholar], p. 153, 9.3, 9.4] and [8 Logachev, D., Zobnin, A. (2017). L-functions of Carlitz Modules, Resultantal Varieties and Rooted Binary Trees, arXiv:1607.06147v3 [math.AG]. [Google Scholar], p. 5, 0.2.4].     

On deformations of triangulated models

This paper is the first part of a project aimed at understanding deformations of triangulated categories, and more precisely their dg and _A∞$A_{\infty }$ models, and applying the resulting theory to the models occurring in the Homological Mirror Symmetry setup. In this first paper, we focus on models of derived and related categories, based upon the classical construction of twisted objects over a dg or _A∞$A_{\infty }$-algebra. For a Hochschild 2 cocycle on such a model, we describe a corresponding “curvature compensating” deformation which can be entirely understood within the framework of twisted objects. We unravel the construction in the specific cases of derived _A∞$A_{\infty }$ and abelian categories, homotopy categories, and categories of graded free qdg-modules. We identify a purity condition on our models which ensures that the structure of the model is preserved under deformation. This condition is typically fulfilled for homotopy categories, but not for unbounded derived categories.     

Gorenstein Right Derived Functors of − ⊗ −with Respect to Semidualizing Modules

We study Gorenstein right derived functors of ? ? ?with respect to semidualizing modules. As applications, some new criteria for a semidualizing module to be dualizing are given provided that R is a ring with a dualizing complex.     

三角范畴的recollement与AR-三角

设{D＇,D,D＇＇;i^＊,i＊=i!,i^!,j!,j^＊=j^!,j＊）是一个recollement,本文证明了当D有AR-三角时,D＇,D＇＇也有AR-三角,并且它们的AR-三角完全可由D中AR-三角诱导．     

Varieties and cohomology of infinitely generated modules

Suppose that k is a field of characteristic p and that G is a finite group having p-rank at least three. Given a regular sequence of length 2 in H*(G, k), we show how to construct an infinitely generated module whose support variety is strictly smaller than the small support of its cohomology. Received: 25 January 2008     

On a class of semicommutative modules

Let R be a ring with identity, M a right R-module and S = End _R (M). In this note, we introduce S-semicommutative, S-Baer, S-q.-Baer and S-p.q.-Baer modules. We study the relations between these classes of modules. Also we prove if M is an S-semicommutative module, then M is an S-p.q.-Baer module if and only if M[x] is an S[x]-p.q.-Baer module, M is an S-Baer module if and only if M[x] is an S[x]-Baer module, M is an S-q.-Baer module if and only if M[x] is an S[x]-q.-Baer module.     

Tensor product of C-injective modules

The purpose of this paper is to calculate all the character tables of Hecke algebras associated with finite Chevalley groups of exceptional type and their maximal parabolic subgroups when they are commutative. In the case when the groups are of classical type, the character values of Hecke algebras are expressed by using the q-Krawtchouk polynomials and the q-Hahn polynomials (See [10] and [15]). On the other hand, the character tables of commutative Hecke algebras associated with exceptional Weyl groups and their maximal parabolic subgroups are given in [12]. In §1, we discuss the structure of Hecke algebras and in §2, we calculate all the character tables of these commutative Hecke algebras associated with finite Chevalley groups of exceptional type. Although some of them are well known, we include them for completeness     

Formal completions and idempotent completions of triangulated categories of singularities

The main goal of this paper is to prove that the idempotent completions of triangulated categories of singularities of two schemes are equivalent if the formal completions of these schemes along singularities are isomorphic. We also discuss Thomason's theorem on dense subcategories and a relation to the negative K-theory.     

From triangulated categories to abelian categories: cluster tilting in a general framework

A general framework for cluster tilting is set up by showing that any quotient of a triangulated category modulo a tilting subcategory (i.e., a maximal 1-orthogonal subcategory) carries an induced abelian structure. These abelian quotients turn out to be module categories of Gorenstein algebras of dimension at most one.      

The isomorphism problem for uniserial modules over an arbitrary ring

Abstract

First, we give a partial solution to the isomorphism problem for uniserial modules of finite length with the help of the morphisms between these modules. Later, under suitable assumptions on the lattice of the submodules, we give a method to partially solve the isomorphism problem for uniserial modules over an arbitrary ring. Particular attention is given to the natural class of uniserial modules defined over algebras given by quivers.     

Complexity of degenerations of modules

A module M over an associative algebra A over an algebraically closed field k is said to degenerate to a module N if N belongs to the closure of the isomorphism class of M in the algebraic variety of d-dimensional A-modules, . We associate a non-negative integer to a degeneration , its complexity, and study its properties. Received: January 30, 2001     

Extension closure of relative syzygy modules

In this paper we introduce the notion of relative syzygy modules.We then study the extensionclosure of the category of modules consisting of relative syzygy modules(resp.relative k-torsionfree modules).     

Rigid Dualizing Complexes Over Commutative Rings

In this paper we present a new approach to Grothendieck duality over commutative rings. Our approach is based on the idea of rigid dualizing complexes, which was introduced by Van den Bergh in the context of noncommutative algebraic geometry. The method of rigidity was modified to work over general commutative base rings in our paper (Yekutieli and Zhang, Trans AMS 360:3211–3248, 2008). In the present paper we obtain many of the important local features of Grothendieck duality, yet manage to avoid lengthy and difficult compatibility verifications. Our results apply to essentially finite type algebras over a regular noetherian finite dimensional base ring, and hence are suitable for arithmetic rings. In the sequel paper (Yekutieli, Rigid dualizing complexes on schemes, in preparation) these results will be used to construct and study rigid dualizing complexes on schemes. This research was supported by the US–Israel Binational Science Foundation. The second author was partially supported by the US National Science Foundation.