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Haruto Murata

Publications and source records attributed to Haruto Murata.

3 recordsLinked to original sources

Quantum imaginary Schur-Weyl duality

We study quiver Hecke algebras of untwisted affine type $A$ with an arbitrary choice of parameters and establish a duality with the Iwahori-Hecke algebra of the symmetric group. The parameter $t$ of the Iwahori-Hecke algebra is explicitly determined by the parameters defining the quiver Hecke algebra. This duality provides a deformation of the imaginary Schur-Weyl duality introduced by Kleshchev and Muth. Furthermore, we prove that the characters of simple modules in the imaginary strata are computed in terms of the dual canonical basis and Kazhdan-Lusztig polynomials, and the characters of standard modules coincide with the PBW vectors of the corresponding quantum group under certain assumptions. In addition, we examine other untwisted affine types, where the quiver Hecke algebra is known to be independent of the choice of parameters and the imaginary Schur-Weyl duality with the symmetric group has been established. As in type $A$, we apply this duality to the computation of characters of simple and standard modules.

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A diagrammatic approach to reflection functors

We construct reflection functors for quiver Hecke algebras associated with arbitrary symmetrizable Kac-Moody algebras, from a higher representation-theoretic viewpoint. These functors provide a categorification of Lusztig's braid group action on the quantum group. Similar functors were recently constructed independently by Kashiwara-Kim-Oh-Park via a different approach. Moreover, we prove that our reflection functors satisfy the braid relations as natural isomorphisms.

math.RT

Affine highest weight structures on module categories over quiver Hecke algebras

We prove that the category of finitely generated graded modules over the quiver Hecke algebra of arbitrary type admits numerous stratifications in the sense of Kleshchev. A direct consequence is that the full subcategory corresponding to the quantum unipotent subgroup associated with any Weyl group element is an affine highest weight category. Our results significantly generalize earlier works by Kato, Brundan, Kleshchev, McNamara and Muth. The key ingredient is a realization of standard modules via determinantial modules. We utilize the technique of R-matrices to study these standard modules.

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