Quantum groups and quantum cohomology

© Astérisque 408, SMF 2019 — In this paper, we study the classical and quantum equivariant cohomology of Nakajima quiver varieties for a general quiver Q. Using a geometric R-matrix formalism, we construct a Hopf algebra YQ, the Yangian of Q, acting on the cohomology of these varieties, and show sev...

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Main Authors: Maulik, D, Okounkov, A
Other Authors: Massachusetts Institute of Technology. Department of Mathematics
Format: Article
Language:English
Published: Societe Mathematique de France 2021
Online Access:https://hdl.handle.net/1721.1/136200
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author Maulik, D
Okounkov, A
author2 Massachusetts Institute of Technology. Department of Mathematics
author_facet Massachusetts Institute of Technology. Department of Mathematics
Maulik, D
Okounkov, A
author_sort Maulik, D
collection MIT
description © Astérisque 408, SMF 2019 — In this paper, we study the classical and quantum equivariant cohomology of Nakajima quiver varieties for a general quiver Q. Using a geometric R-matrix formalism, we construct a Hopf algebra YQ, the Yangian of Q, acting on the cohomology of these varieties, and show several results about their basic structure theory. We prove a formula for quantum multiplication by divisors in terms of this Yangian action. The quantum connection can be identified with the trigonometric Casimir connection for YQ; equivalently, the divisor operators correspond to certain elements of Baxter subalgebras of YQ. A key role is played by geometric shift operators which can be identified with the quantum KZ difference connection. In the second part, we give an extended example of the general theory for moduli spaces of sheaves on C2, framed at infinity. Here, the Yangian action is analyzed explicitly in terms of a free field realization; the corresponding R-matrix is closely related to the reflection operator in Liouville field theory. We show that divisor operators generate the quantum ring, which is identified with the full Baxter subalgebras. As a corollary of our construction, we obtain an action of the W-algebra Wgl(r) on the equivariant cohomology of rank r moduli spaces, which implies certain conjectures of Alday, Gaiotto, and Tachikawa.
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spelling mit-1721.1/1362002024-01-03T17:59:22Z Quantum groups and quantum cohomology Maulik, D Okounkov, A Massachusetts Institute of Technology. Department of Mathematics © Astérisque 408, SMF 2019 — In this paper, we study the classical and quantum equivariant cohomology of Nakajima quiver varieties for a general quiver Q. Using a geometric R-matrix formalism, we construct a Hopf algebra YQ, the Yangian of Q, acting on the cohomology of these varieties, and show several results about their basic structure theory. We prove a formula for quantum multiplication by divisors in terms of this Yangian action. The quantum connection can be identified with the trigonometric Casimir connection for YQ; equivalently, the divisor operators correspond to certain elements of Baxter subalgebras of YQ. A key role is played by geometric shift operators which can be identified with the quantum KZ difference connection. In the second part, we give an extended example of the general theory for moduli spaces of sheaves on C2, framed at infinity. Here, the Yangian action is analyzed explicitly in terms of a free field realization; the corresponding R-matrix is closely related to the reflection operator in Liouville field theory. We show that divisor operators generate the quantum ring, which is identified with the full Baxter subalgebras. As a corollary of our construction, we obtain an action of the W-algebra Wgl(r) on the equivariant cohomology of rank r moduli spaces, which implies certain conjectures of Alday, Gaiotto, and Tachikawa. 2021-10-27T20:34:14Z 2021-10-27T20:34:14Z 2019-01-01 2021-05-24T17:31:18Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/136200 en 10.24033/ast.1074 Asterisque Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Societe Mathematique de France arXiv
spellingShingle Maulik, D
Okounkov, A
Quantum groups and quantum cohomology
title Quantum groups and quantum cohomology
title_full Quantum groups and quantum cohomology
title_fullStr Quantum groups and quantum cohomology
title_full_unstemmed Quantum groups and quantum cohomology
title_short Quantum groups and quantum cohomology
title_sort quantum groups and quantum cohomology
url https://hdl.handle.net/1721.1/136200
work_keys_str_mv AT maulikd quantumgroupsandquantumcohomology
AT okounkova quantumgroupsandquantumcohomology