Cohen-Montgomery duality对于双模和Morita类型的奇异等价

Dualizing Complexes, Morita Equivalence and the Derived Picard Group of a Ring

Two rings A and B are said to be derived Morita equivalent if their derived categories of modules are equivalent. By results of Rickard, if A and B are derived Morita equivalent algebras over a field k, then there is a complex of bimodules T s.t. the derived tensor product with T is an equivalence. The complex T is called a tilting complex. When B = A the isomorphism classes of tilting complexes T form the derived Picard group DPic(A). We prove that when the algebra A is either local or commutative, then any derived Morita equivalent algebra B is actually Morita equivalent. So we can compute D…

Gorenstein homological aspects of monomorphism categories via Morita rings

For any ring R the category of monomorphisms is a full subcategory of the morphsim category over R, where the latter is equivalent to the module category of the triangular matrix ring with entries the ring R. In this work, we consider the monomorphism category as a full subcategory of the module category over the Morita ring with all entries the ring R and zero bimodule homomorphisms. This approach provides an interesting link between Morita rings and monomorphism categories. The aim of this paper is two-fold. First, we construct Gorenstein-projective modules over Morita rings with zero bimodu…

Singular equivalences of Morita type with level, Gorenstein algebras, and universal deformation rings

Let $\mathbf{k}$ be a field of arbitrary characteristic, let $Λ$ be a finite dimensional $\mathbf{k}$-algebra, and let $V$ be an indecomposable finitely generated non-projective Gorenstein-projective left $Λ$-module whose stable endomorphism ring is isomorphic to $\mathbf{k}$. In this article, we prove that the universal deformation rings $R(Λ,V)$ and $R(Λ,Ω_ΛV)$ are isomorphic, where $Ω_ΛV$ denotes the first syzygy of $V$ as a left $Λ$-module. We also prove the following result. Assume that $Λ$ is Gorenstein and that $Γ$ is another Gorenstein $\mathbf{k}$-algebra such that there exists $\ell …

Pivotal tricategories and a categorification of inner-product modules

This article investigates duals for bimodule categories over finite tensor categories. We show that finite bimodule categories form a tricategory and discuss the dualities in this tricategory using inner homs. We consider inner-product bimodule categories over pivotal tensor categories with additional structure on the inner homs. Inner-product module categories are related to Frobenius algebras and lead to the notion of $*$-Morita equivalence for pivotal tensor categories. We show that inner-product bimodule categories form a tricategory with two duality operations and an additional pivotal st…

On stable equivalences with endopermutation source

We show that a bimodule between block algebras which has a fusion stable endopermutation module as a source and which induces Morita equivalences between centralisers of nontrivial subgroups of a defect group induces a stable equivalence of Morita type; this is a converse to a theorem of Puig. The special case where the source is trivial has long been known by many authors. The earliest instance for a result deducing a stable equivalence of Morita type from local Morita equivalences with possibly nontrivial endopermutation source is due to Puig, in the context of blocks with abelian defect gro…

有限预张量范畴与有限张量范畴的莫里塔等价

Finite Pre-Tensor Categories that are Morita Equivalent to Finite Tensor Categories

本文研究有限预张量范畴与有限张量范畴的莫里塔等价问题，证明预张量范畴的莫里塔等价当且仅当其Drinfeld中心为有限张量范畴。

Strong fusion control and stable equivalences

This article is dedicated to the proof of the following theorem. Let G be a finite group, p be a prime number, and e be a p-block of G. Assume that the centraliser C_G(P) of an e-subpair (P,e_P) "strongly" controls the fusion of the block e, and that a defect group of e is either abelian or (for odd p) has a non-cyclic center. Then there exists a stable equivalence of Morita type between the block algebras OGe and OC_G(P)e_P, where O is a complete discrete valuation ring of residual characteristic p. This stable equivalence is constructed by gluing together a family of local Morita equivalence…

Inductions and restrictions for stable equivalences of Morita type

In this paper, we present two methods, induction and restriction procedures, to construct new stable equivalences of Morita type. Suppose that a stable equivalence of Morita type between two algebras $A$ and $B$ is defined by a $B$-$A$-bimodule $N$. Then, for any finite admissible set $Φ$ and any generator $X$ of the $A$-module category, the $Φ$-Auslander-Yoneda algebras of $X$ and $N\otimes_AX$ are stably equivalent of Morita type. Moreover, under certain conditions, we transfer stable equivalences of Morita type between $A$ and $B$ to ones between $eAe$ and $fBf$, where $e$ and $f$ are idemp…

Eilenberg-Watts calculus for finite categories and a bimodule Radford $S^4$ theorem

We obtain Morita invariant versions of Eilenberg-Watts type theorems, relating Deligne products of finite linear categories to categories of left exact as well as of right exact functors. This makes it possible to switch between different functor categories as well as Deligne products, which is often very convenient. For instance, we can show that applying the equivalence from left exact to right exact functors to the identity functor, regarded as a left exact functor, gives a Nakayama functor. The equivalences of categories we exhibit are compatible with the structure of module categories ove…

Reduction techniques of singular equivalences

It is shown that a singular equivalence induced by tensoring with a suitable complex of bimodules defines a singular equivalence of Morita type with level, in the sense of Wang. This result is applied to homological ideals and idempotents to produce new reduction techniques for testing the properties of syzygy-finite and injectives generation of finite dimensional algebras over a field.

Invertible Bimodules, Miyashita Action in Monoidal Categories and Azumaya Monoids

In this paper we introduce and study Miyashita action in the context of monoidal categories aiming by this to provide a common framework of previous studies in the literature. We make a special emphasis of this action on Azumaya monoids. To this end, we develop the theory of invertible bimodules over different monoids (a sort of Morita contexts) in general monoidal categories as well as their corresponding Miyashita action. Roughly speaking, a Miyashita action is a homomorphism of groups from the group of all isomorphic classes of invertible subobjects of a given monoid to its group of automor…

等秩局部theta对应作为强Morita等价

Equal rank local theta correspondence as a strong Morita equivalence

本文证明等秩约化对偶对的theta对应双射可由两个C*-代数表示范畴间的Morita等价实现，并由此推出双射的函子性、连续性及特征标与形式度的相关性质。

奇异范畴的增强 Auslander-Reiten 对偶性与 Morita 定理

Enhanced Auslander-Reiten duality and Morita theorem for singularity categories

本文建立了Gorenstein环奇异范畴与有限维代数cluster范畴间的Morita定理，通过寻找倾斜对象构造三角等价及典范dg增强间的拟等价，并证明了对称阶奇异范畴的双模Calabi-Yau性质以提升Auslander-Reiten对偶性，应用于多种环类。