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Related papers: Affine flag varieties and quantum symmetric pairs

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We use Drinfeld style generators and relations to define an algebra $\mathfrak{U}_n$ which is a ``$q=0$'' version of the affine quantum group of $\mathfrak{gl}_n.$ We then use the convolution product on the equivariant $K$-theory of…

Representation Theory · Mathematics 2025-05-28 Sergey Arkhipov , Mikhail Mazin

We provide a geometric realization of the quasi-split affine $\imath$quantum group of type AIII$_{2n-1}^{(\tau)}$ in terms of equivariant K-groups of non-connected Steinberg varieties of type C. This uses a new Drinfeld type presentation of…

Representation Theory · Mathematics 2026-05-29 Changjian Su , Weiqiang Wang

We introduce an analogue of the $q$-Schur algebra associated to Coxeter systems of type $\hat A_{n-1}$. We give two constructions of this algebra. The first construction realizes the algebra as a certain endomorphism algebra arising from an…

q-alg · Mathematics 2008-02-03 R. M. Green

The canonical basis for quantized universal enveloping algebras associated to the finite--dimensional simple Lie algebras, was introduced by Lusztig. The principal technique is the explicit construction (via the braid group action) of a…

Quantum Algebra · Mathematics 2007-05-23 Jonathan Beck , Vyjayanthi Chari , Andrew Pressley

A quantum symmetric pair consists of a quantum group $\mathbf U$ and its coideal subalgebra ${\mathbf U}^{\imath}_{\boldsymbol{\varsigma}}$ with parameters $\boldsymbol{\varsigma}$ (called an $\imath$quantum group). We initiate a Hall…

Representation Theory · Mathematics 2022-05-30 Ming Lu , Weiqiang Wang

According to the Hall algebras of quivers with automorphisms under Lusztig's construction, the polynominal forms of several structure coefficients for quantum groups of all finite types are presented in this note. We first provide a…

Representation Theory · Mathematics 2025-10-30 Yixin Lan , Yumeng Wu , Jie Xiao

In this paper we construct equivalences of monoidal categories relating three geometric or representation-theoretic categorical incarnations of the affine Hecke algebra of a connected reductive algebraic group $G$ over a field of positive…

Representation Theory · Mathematics 2024-07-08 Roman Bezrukavnikov , Simon Riche

Quantum toroidal algebras (or double affine quantum algebras) are defined from quantum affine Kac-Moody algebras by using the Drinfeld quantum affinization process. They are quantum groups analogs of elliptic Cherednik algebras (elliptic…

Quantum Algebra · Mathematics 2010-04-07 David Hernandez

We prove that the Schubert structure constants of the quantum $K$-theory ring of any minuscule flag variety or quadric hypersurface have signs that alternate with codimension. We also prove that the powers of the deformation parameter $q$…

Algebraic Geometry · Mathematics 2026-03-24 Anders S. Buch , Pierre-Emmanuel Chaput , Leonardo C. Mihalcea , Nicolas Perrin

A geometric construction of Lusztig's modified quantum algebra of symmetric type is presented by using certain localized equivariant derived categories of double framed representation varieties of quivers.

Representation Theory · Mathematics 2012-09-19 Yiqiang Li

We study the geometry of equicharacteristic partial affine flag varieties associated to tamely ramified groups $G$ in characteristics $p>0$ dividing the order of the fundamental group $\pi_1(G_{\text{der}})$. We obtain that most Schubert…

Algebraic Geometry · Mathematics 2022-10-06 Thomas J. Haines , João Lourenço , Timo Richarz

An important breakthrough in understanding the geometry of Schubert varieties was the introduction of the notion of Frobenius split varieties and the result that the flag varieties G/P are Frobenius split. The aim of this article is to give…

Quantum Algebra · Mathematics 2007-05-23 Shrawan Kumar , Peter Littelmann

We define the double quantum affinization $\ddot{\mathrm{U}}_q(\mathfrak a_1)$ of type $\mathfrak{a}_1$ as a topological Hopf algebra. We prove that it admits a subalgebra $\ddot{\mathrm{U}}_q'(\mathfrak a_1)$ whose completion is…

Quantum Algebra · Mathematics 2019-03-04 Elie Mounzer , Robin Zegers

We propose a construction of some canonical bases for quantum loop algebras of Kac-Moody algebras. We consider a smooth projective curve X, a group of automorphism G of X such that X/G=P^1, and we consider some Quot schemes of G-equivariant…

Quantum Algebra · Mathematics 2007-05-23 Olivier Schiffmann

This paper studies affine Deligne-Lusztig varieties in the affine flag manifold of a split group. Among other things, it proves emptiness for certain of these varieties, relates some of them to those for Levi subgroups, extends previous…

Algebraic Geometry · Mathematics 2014-01-14 Ulrich Goertz , Thomas J. Haines , Robert E. Kottwitz , Daniel C. Reuman

We produce 2-representations of the positive part of affine quantum enveloping algebras on their finite-dimensional counterparts in type $A_n$. These 2-representations naturally extend the right-multiplication 2-representation of…

Quantum Algebra · Mathematics 2026-04-16 Sam Qunell

We offer a complete classification of right coideal subalgebras which contain all group-like elements for the multiparameter version of the quantum group $U_q(\mathfrak{sl}_{n+1})$ provided that the main parameter $q$ is not a root of 1. As…

Quantum Algebra · Mathematics 2008-04-14 V. Kharchenko , A. V. Lara Sagahon

Given a smooth curve $C$, we define and study analogues of KLR algebras and quiver Schur algebras, where quiver representations are replaced by torsion sheaves on $C$. In particular, they provide a geometric realization for certain…

Representation Theory · Mathematics 2023-11-02 Ruslan Maksimau , Alexandre Minets

Let $ G $ be a connected, simply connected semisimple algebraic group over the complex number field, and let $ K $ be the fixed point subgroup of an involutive automorphism of $ G $ so that $ (G, K) $ is a symmetric pair. We take parabolic…

Representation Theory · Mathematics 2013-07-30 Xuhua He , Kyo Nishiyama , Hiroyuki Ochiai , Yoshiki Oshima

In this paper, we consider graded associative conformal algebras. The class of these objects includes pseudo-algebras over non-cocommutative Hopf algebras of regular functions on some linear algebraic groups. In particular, an associative…

Quantum Algebra · Mathematics 2015-09-17 Pavel Kolesnikov