Ar-Quiver Approach to Affine Canonical Basis Elements

Smallness problem for quantum affine algebras and quiver varieties

The geometric small property (Borho-MacPherson) of projective morphisms implies a description of their singularities in terms of intersection homology. In this paper we solve the smallness problem raised by Nakajima (math.QA/0105173) for certain resolutions of quiver varieties (analogs of the Springer resolution) : for Kirillov-Reshetikhin modules of simply-laced quantum affine algebras, we characterize explicitly the Drinfeld polynomials corresponding to the small resolutions. We use an elimination theorem for monomials of Frenkel-Reshetikhin q-characters that we establish for non necessarily…

仿射最高权结构在箭图Hecke代数上的模范畴中的应用

Affine highest weight structures on module categories over quiver Hecke algebras

本文证明任意类型箭图Hecke代数的有限生成分次模范畴具有多种Kleshchev分层，从而得到与Weyl群元素相关的量子幺正子群范畴为仿射最高权范畴，推广了多项早期工作，关键利用行列式模和R-矩阵技术。

Canonical basis linearity regions arising from quiver representations

In this paper we show that there is a link between the combinatorics of the canonical basis of a quantized enveloping algebra and the monomial bases of the second author arising from representations of quivers. We prove that some reparametrization functions of the canonical basis, arising from the link between Lusztig's approach to the canonical basis and the string parametrization of the canonical basis, are given on a large region of linearity by linear functions arising from these monomial basis for a quantized enveloping algebra.

Twisted and folded Auslander-Reiten quivers and applications to the representation theory of quantum affine algebras

In this paper, we introduce twisted and folded AR-quivers of type $A_{2n+1}$, $D_{n+1}$, $E_6$ and $D_4$ associated to (triply) twisted Coxeter elements. Using the quivers of type $A_{2n+1}$ and $D_{n+1}$, we describe the denominator formulas and Dorey's rule for quantum affine algebras $U'_q(B^{(1)}_{n+1})$ and $U'_q(C^{(1)}_{n})$, which are important information of representation theory of quantum affine algebras. More precisely, we can read the denominator formulas for $U'_q(B^{(1)}_{n+1})$ (resp. $U'_q(C^{(1)}_{n})$) using certain statistics on any folded AR-quiver of type $A_{2n+1}$ (resp…

Symmetric quiver Hecke algebras and R-matrices of Quantum affine algebras IV

Let $U'_q(\mathfrak{g})$ be a twisted affine quantum group of type $A_{N}^{(2)}$ or $D_{N}^{(2)}$ and let $\mathfrak{g}_{0}$ be the finite-dimensional simple Lie algebra of type $A_{N}$ or $D_{N}$. For a Dynkin quiver of type $\mathfrak{g}_{0}$, we define a full subcategory ${\mathcal C}_{Q}^{(2)}$ of the category of finite-dimensional integrable $U'_q(\mathfrak{g})$-modules, a twisted version of the category ${\mathcal C}_{Q}$ introduced by Hernandez and Leclerc. Applying the general scheme of affine Schur-Weyl duality, we construct an exact faithful KLR-type duality functor ${\mathcal F}_{Q}…

Auslander-Reiten quiver of type A and generalized quantum affine Schur-Weyl duality

The quiver Hecke algebra $R$ can be also understood as a generalization of the affine Hecke algebra of type $A$ in the context of the quantum affine Schur-Weyl duality by the results of Kang, Kashiwara and Kim. On the other hand, it is well-known that the Auslander-Reiten(AR) quivers $Γ_Q$ of finite simply-laced types have a deep relation with the positive roots systems of the corresponding types. In this paper, we present explicit combinatorial descriptions for the AR-quivers $Γ_Q$ of finite type $A$. Using the combinatorial descriptions, we can investigate relations between finite dimensiona…

Nakajima箭图簇、仿射晶体与Auslander-Reiten箭图的组合学

Nakajima quiver varieties, affine crystals and combinatorics of Auslander-Reiten quivers

本文建立了A型和D型单李代数晶体基两种实现间的显式晶体同构，给出了Lusztig箭图簇不可约分支的同调描述，并通过A型提升算子实现了Kirillov-Reshetikhin晶体的几何构造。

Quiver varieties and finite dimensional representations of quantum affine algebras

We study finite dimensional representations of the quantum affine algebra, using geometry of quiver varieties introduced by the author. As an application, we obtain character formulas expressed in terms of intersection cohomologies of quiver varieties.

Auslander-Reiten quiver of type D and generalized quantum affine Schur-Weyl duality

We first provide an explicit combinatorial description of the Auslander-Reiten quiver $Γ^Q$ of finite type $D$. Then we can investigate the categories of finite dimensional representations over the quantum affine algebra $U_q'(D^{(i)}_{n+1})$ $(i=1,2)$ and the quiver Hecke algebra $R_{D_{n+1}}$ associated to $D_{n+1}$ $(n \ge 3)$, by using the combinatorial description and the generalized quantum affine Schur-Weyl duality functor. As applications, we can prove that Dorey's rule holds for the category $\Rep(R_{D_{n+1}})$ and prove an interesting difference between multiplicity free positive roo…

Affine quivers of type A and canonical bases

Let Q be an affine quiver of type A. Let C be the associated generalized Cartan matrix. Let U^- be the negative part of the quantized enveloping algebra attached to C. In terms of perverse sheaves on the moduli space of representations of a quiver, Lusztig constructed U geometrically and gave a canonical basis B of U^- at the same time. The simple perverse sheaves which enter B are defined abstractly in general. In Lusztig's paper [L2], by using McKay's correspondence, he gave a description of these canonical basis elements in affine cases, i.e. specifying the corresponding supports and local …

驯服箭图与仿射基II：非对称情形

Tame quivers and affine bases II: nonsimply-laced cases

本文用Ringel-Hall代数方法将仿射典范基推广到一般对称化情形，证明所得bar不变基与Lusztig带符号典范基一致，并在$\tilde{B}_n,\tilde{C}_n$型中直接给出典范基。

Hall代数与移位量子仿射代数

Hall algebras and shifted quantum affine algebras

本文提出了一种移位量子仿射代数变形的几何构造方法，将其实现为特定quiver表示范畴的Hall代数，揭示了其与Coulomb分支及受限表示的联系。

Graded quiver varieties, quantum cluster algebras and dual canonical basis

Inspired by a previous work of Nakajima, we consider perverse sheaves over acyclic graded quiver varieties and study the Fourier-Sato-Deligne transform from a representation theoretic point of view. We obtain deformed monoidal categorifications of acyclic quantum cluster algebras with specific coefficients. In particular, the (quantum) positivity conjecture is verified whenever there is an acyclic seed in the (quantum) cluster algebra. In the second part of the paper, we introduce new quantizations and show that all quantum cluster monomials in our setting belong to the dual canonical basis of…

有向图品种与对偶规范基

Quiver varieties and dual canonical bases

本文综述了量子群和$\imath$量子群对偶规范基理论的最新进展，介绍了$\imath$有向图代数，并展示了其在ADE类型准分裂$\imath$量子群中的两种实现方式，同时解决了若干猜想。

Remarks on PBW bases of Ringel-Hall algebras of cyclic quivers

In this paper, we give a recursive formula for the interesting PBW basis $E_{A}$ of composition subalgebras of Ringel-Hall algebras $\fkH_\vartri(n)$ of cyclic quivers after \cite{DengDuXiao2007generic}, and another construction of canonical bases of $\U_v^+(\wih{\fks\fkl}_n)$ from the monomial bases $m^{(A)}$ follow \cite{DuZhaomultiplication}. As an application, we will determined all the canonical basis of $\U_v^+(\wih{\fks\fkl}_2)$ associated with modules of Lowery length $\leqs3$. Finally, we will discuss the relation of canonical bases of Ringel-Hall algebras and those of affine quantum …

A Quiver Construction of Symmetric Crystals

In the recent papers with Masaki Kashiwara, the author introduced the notion of symmetric crystals and presented the Lascoux-Leclerc-Thibon-Ariki type conjectures for the affine Hecke algebras of type $B$. Namely, we conjectured that certain composition multiplicities and branching rules for the affine Hecke algebras of type $B$ are described by using the lower global basis of symmetric crystals of $V_θ(λ)$. In this paper, we prove the existence of crystal bases and global bases of $V_θ(0)$ for any symmetric quantized Kac-Moody algebra by using a geometry of quivers (with a Dynkin diagram invo…

Representations of tame quivers and affine canonical bases

An integral PBW-basis of type $A_1^{(1)}$ has been constructed by Zhang [Z] and Chen [C] using the Auslander-Reiten quiver of the Kronecker quiver. We associate a geometric order to elements in this basis following an idea of Lusztig [L1] in the case of finite type. This leads to an algebraic realization of a bar-invariant basis of $\uq2$. For any affine symmetric type, we obtain an integral PBW-basis of the generic composition algebra, by using an algebraic construction of the integral basis for a tube in [DDX], an embedding of the module category of the Kronecker quiver into the module categ…

Equivalence between module categories over quiver Hecke algebras and Hernandez-Leclerc's categories in general types

We prove in full generality that the generalized quantum affine Schur-Weyl duality functor, introduced by Kang-Kashiwara-Kim, gives an equivalence between the category of finite-dimensional modules over a quiver Hecke algebra and a certain full subcategory of finite-dimensional modules over a quantum affine algebra which is a generalization of the Hernandez-Leclerc's category $\mathcal{C}_Q$. This was previously proved in untwisted $ADE$ types by Fujita using the geometry of quiver varieties, which is not applicable in general. Our proof is purely algebraic, and so can be extended uniformly to…

有向图模与量子环形代数

Quiver moduli and quantum loop algebras

本文通过临界K理论将量子环形代数中所有简单模的q-特征与有向图模空间的欧拉特征联系起来。

Symmetric quiver Hecke algebras and R-matrices of quantum affine algebras

Let $J$ be a set of pairs consisting of good modules over an affine quantum algebra and invertible elements. The distribution of poles of the normalized R-matrices yields Khovanov-Lauda-Rouquier algebras $R^J$. We define a functor $F$ from the category $S_J$ of finite-dimensional graded $R^J$-modules to the category of finite-dimensional integrable $U_q(g)$-modules. The functor $F$ sends convolution products of $R^J$-modules to tensor products of $U_q(g)$-modules. It is exact if $R^J$ is of finite type A,D,E. When $J$ is the vector representation of $A^{(1)}_{n-1}$, we recover the affine Schur…

Tame 箭图与仿射基 I：典范基的霍尔代数方法

Tame quivers and affine bases I: a Hall algebra approach to the canonical bases

本文针对仿射型量子群，利用tame箭图表示导出的PBW基构造bar不变基，证明其与Lusztig典范基一致并给出双射，指标集按特定模与对称群不可约特征有序排列，方法推广自Deng-Du-Xiao的工作。

分圆双仿射Hecke代数的Harish-Chandra同构

Harish-Chandra isomorphism for cyclotomic double affine Hecke algebras

本文证实了Braverman–Etingof–Finkelberg猜想，证明分圆双仿射Hecke代数的球面子代数同构于循环箭图的量子化乘法箭图簇，并给出其与平移量子环面代数的同构关系。

Rational Ringel-Hall algebras, Hall polynomials of affine type and Canonical bases

In this paper, the rational Ringel-Hall algebras for tame quivers are introduced and are identified with the positive part of the quantum extended Kac-Moody algebras. By using the rational Ringel-Hall algebras, we show that the existence of Hall polynomials for tame quiver algebras. The PBW bases are constructed and new classes of perverse sheaves are shown to have strong purity property. These allows us to construct the canonical bases of the positive part of the quantum extended Kac-Moody algebras.

Categorical action of the extended braid group of affine type A

Using a quiver algebra of a cyclic quiver, we construct a faithful categorical action of the extended braid group of affine type A on its bounded homotopy category of finitely generated projective modules. The algebra is trigraded and we identify the trigraded dimensions of the space of morphisms of this category with intersection numbers coming from the topological origin of the group.

Quiver varieties and t-analogs of q-characters of quantum affine algebras

Let us consider a specialization of an untwisted quantum affine algebra of type $ADE$ at a nonzero complex number, which may or may not be a root of unity. The Grothendieck ring of its finite dimensional representations has two bases, simple modules and standard modules. We identify entries of the transition matrix with special values of ``computable'' polynomials, similar to Kazhdan-Lusztig polynomials. At the same time we ``compute'' $q$-characters for all simple modules. The result is based on ``computations'' of Betti numbers of graded/cyclic quiver varieties. (The reason why we put `` '' …

从量子差分方程到仿射A型箭图簇的Dubrovin联络

From quantum difference equation to Dubrovin connection of affine type A quiver varieties

本文延续前期工作，通过给出量子差分算子的良好表示并分析节点极限下的联络矩阵，证明了仿射A型箭图簇的量子差分方程退化极限为Dubrovin联络，其单值表示由单值算子生成。

Quiver $D$-Modules and Homology of Local Systems over an Arrangement of Hyperplanes

Let $C$ be an arrangement of affine hyperplanes in a complex affine space $X$, $D$ the ring of algebraic differential operators on $X$. We define a category of quivers associated with $C$. A quiver is a collection of vector spaces, attached to strata of the arrangement, and suitable linear maps between the vector spaces . To a quiver we assign a $D$-module on $X$, called the quiver $D$-module. We describe basic operations for $D$-modules in terms of linear algebra of quivers. We give an explicit construction of a free resolution of a quive $D$-module and use the construction to describe the as…

循环有向图的CoHA与有理Yangian的积分形式

CoHA of Cyclic Quivers and an Integral Form of Affine Yangians

本文研究了循环有向图的CoHA，揭示其与有理Yangian的积分形式的关系，并探讨了相关代数结构与猜想。

仿射基的几何实现：Kronecker箭图情形

Geometric realization of affine bases: the Kronecker quiver case

本文从几何角度研究Kronecker箭图量子包络代数负部分中PBW基与标准基之间的转移矩阵，通过旗层复形构造PBW基元素的几何实现，并证明转移系数由交上同调复形限制到小子层的局部系统重数决定。

仿射型$A$箭图簇的量子差分方程 I：一般构造

Quantum difference equation for the affine type $A$ quiver varieties I: General Construction

本研究借鉴已有思路，用量子环面代数构造仿射型$A$箭图簇的量子差分方程，定义了泛$R$矩阵作用下的箭图簇墙集并证明其等价性，还推导了两类空间的显式算子以示例说明构造。

The Hall algebra of a cyclic quiver and canonical bases of the Fock space

We prove that the Hall algebra U^-_n of the cyclic quiver of type A^(1)_{n-1} decomposes as a direct product of the quantum negative nilpotent subalgebra U_q^-(\hat{sl}_{n)) and C[q,q^{-1},z_1,z_2...]. We use this to prove a conjecture of Varagnolo and Vasserot in math/9803023 relating the canonical basis of U^-_n and the canonical basis of the level 1 Fock space representation of U_q(\hat{sl}_n) introduced by Leclerc and Thibon. This yields a proof of the positivity conjecture of Lascoux, Leclerc and Thibon, and a q-analogue of the Lusztig character formula for simple modules of the quantum g…

Elliptic Quantum Toroidal Algebra $U_{q,t,p}(gl_{1,tor})$ and Affine Quiver Gauge Theories

We introduce a new elliptic quantum toroidal algebra $U_{q,t,p}(gl_{1,tor})$. Various representations in the quantum toroidal algebra $U_{q,t}(gl_{1,tor})$ are extended to the elliptic case including the level (0,0) representation realized by using the elliptic Ruijsenaars difference operator. Intertwining operators of $U_{q,t,p}(gl_{1,tor})$-modules w.r.t. the Drinfeld comultiplication are also constructed. We show that $U_{q,t,p}(gl_{1,tor})$ gives a realization of the affine quiver $W$-algebra $W_{q,t}(Γ(\widehat{A}_0))$ proposed by Kimura-Pestun. This realization turns out to be useful to …

仿射 $\mathcal{W}$-代数与来自三维 $\mathcal N=4$ 非阿贝尔箭图规范理论的 Miura 映射

Affine $\mathcal{W}$-algebras and Miura maps from 3d $\mathcal N=4$ non-Abelian quiver gauge theories

本文研究三维 $\mathcal{N}=4$ 线性箭图规范理论 H-扭转得到的顶点算子代数，揭示其与希格斯分支及仿射 $\mathcal{W}$-代数的关系，并提出箭图约化算法以系统构造新自由场实现。

Cluster realization of Weyl groups and $q$-characters of quantum affine algebras

We consider an infinite quiver $Q(\mathfrak{g})$ and a family of periodic quivers $Q_m(\mathfrak{g})$ for a finite dimensional simple Lie algebra $\mathfrak{g}$ and $m \in \mathbb{Z}_{>1}$. The quiver $Q(\mathfrak{g})$ is essentially same as what introduced by Hernandez and Leclerc for the quantum affine algebra. We construct the Weyl group $W(\mathfrak{g})$ as a subgroup of the cluster modular group for $Q_m(\mathfrak{g})$, in a similar way as what studied by the author, Ishibashi and Oya, and study its applications to the $q$-characters of quantum non-twisted affine algebras $U_q(\hat{\mathf…

Lusztig 层、特征循环与 Nakajima 箭图簇的 Borel-Moore 同调

Lusztig sheaves, characteristic cycles and the Borel-Moore homology of Nakajima's quiver varieties

本文利用特征循环构建量子群典范基到 Nakajima 箭图簇 Borel-Moore 同调的态射，证明整数实现并给出张量积簇同构猜想的新证明。

Twisted Coxeter elements and folded AR-quivers via Dynkin diagram automorphisms: I

We introduce and study the twisted adapted $r$-cluster point and its combinatorial Auslander-Reiten quivers, called twisted AR-quivers and folded AR-quivers, of type $A_{2n+1}$ which are closely related to twisted Coxeter elements and the non-trivial Dynkin diagram automorphism. As applications of the study, we prove that folded AR-quivers encode crucial information on the representation theory of quantum affine algebra $U_q'(B^{(1)}_{n+1})$ such as Dorey's rule and denominator formulas.

$t$--analogs of $q$--characters of quantum affine algebras of type $E_6$, $E_7$, $E_8$

We compute $t$--analogs of $q$--characters of all $l$--fundamental representations of the quantum affine algebras of type $E_6^{(1)}$, $E_7^{(1)}$, $E_8^{(1)}$ by a supercomputer. In particular, we prove the fermionic formula for Kirillov-Reshetikhin modules conjectured by Hatayama et al. (math.QA/9812022) for these classes of representations. We also give explicitly the monomial realization of the crystal of the corresponding fundamental representations of the qunatum enveloping algebras associated with finite dimensional Lie algebras of types $E_6$, $E_7$, $E_8$. These are computations of Be…

箭图Hall代数中的迷向尖点函数

Isotropic cuspidal functions in the Hall algebra of a quiver

本文通过仿射无环箭图表示范畴的结构，确定了正则尖点函数空间上的显式线性形式并证明迷向尖点维数具有仿射支撑，从而给出任意箭图迷向尖点函数的显式描述，并由此为Berenstein-Greenstein猜想提供新证明且蕴含Bozec-Schiffmann正性猜想。

Generalized McKay quivers of rank three

For each finite subgroup G of SL(n, C), we introduce the generalized Cartan matrix C_{G} in view of McKay correspondence from the fusion rule of its natural representation. Using group theory, we show that the generalized Cartan matrices have similar favorable properties such as positive semi-definiteness as in the classical case of affine Cartan matrices (the case of SL(2,C)). The complete McKay quivers for SL(3,C) are explicitly described and classified based on representation theory.

Mutation-Periodic Quivers, Integrable Maps and Associated Poisson Algebras

We consider a class of map, recently derived in the context of cluster mutation. In this paper we start with a brief review of the quiver context, but then move onto a discussion of a related Poisson bracket, along with the Poisson algebra of a special family of functions associated with these maps. A bi-Hamiltonian structure is derived and used to construct a sequence of Poisson commuting functions and hence show complete integrability. Canonical coordinates are derived, with the map now being a canonical transformation with a sequence of commuting invariant functions. Compatibility of a pair…