Vertex Operators, Solvable Lattice Models and Metaplectic Whittaker Functions
Vertex Operators, Solvable Lattice Models and Metaplectic Whittaker Functions
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DOI：
10.1007/s00220-020-03842-w
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发表时间：
2018-06
影响因子：
2.4
通讯作者：
Ben Brubaker;Valentin Buciumas;D. Bump;H. Gustafsson
中科院分区：
文献类型：
--
作者：
Ben Brubaker;Valentin Buciumas;D. Bump;H. Gustafsson
We show that spherical Whittaker functions on ann-fold cover of the general linear group arise naturally from the quantum Fock space representation ofintroduced by Kashiwara, Miwa and Stern (KMS). We arrive at this connection by reconsidering the solvable lattice models known as “metaplectic ice” whose partition functions are metaplectic Whittaker functions. First, we show that a certain Hecke action on metaplectic Whittaker coinvariants agrees (up to twisting) with a Hecke action of Ginzburg, Reshetikhin, and Vasserot arising in quantum affine Schur-Weyl duality. This allows us to expand the framework of KMS by Drinfeld twisting to introduce Gauss sums into the quantum wedge, which are necessary for connections to metaplectic forms. Our main theorem interprets the row transfer matrices of this ice model as “half” vertex operators on quantum Fock space that intertwine with the action of. In the process, we introduce new symmetric functions termedmetaplectic symmetric functionsand explain how they are related to Whittaker functions on ann-fold metaplectic cover of. These resembleLLT polynomialsorribbon symmetric functionsintroduced by Lascoux, Leclerc and Thibon, and in fact the metaplectic symmetric functions are (up to twisting) specializations ofsupersymmetric LLT polynomialsdefined by Lam. Indeed Lam constructed families of symmetric functions from Heisenberg algebra actions on the Fock space commuting with the-action. The Heisenberg algebra is independent of Drinfeld twisting of the quantum group. We explain that half vertex operators agree with Lam’s construction and this interpretation allows for many new identities for metaplectic symmetric and Whittaker functions, including Cauchy identities. While both metaplectic symmetric functions and LLT polynomials can be related to vertex operators on the quantum Fock space, only metaplectic symmetric functions are connected to solvable lattice models.
We show that spherical Whittaker functions on ann-fold cover of the general linear group arise naturally from the quantum Fock space representation ofintroduced by Kashiwara, Miwa and Stern (KMS). We arrive at this connection by reconsidering the solvable lattice models known as “metaplectic ice” whose partition functions are metaplectic Whittaker functions. First, we show that a certain Hecke action on metaplectic Whittaker coinvariants agrees (up to twisting) with a Hecke action of Ginzburg, Reshetikhin, and Vasserot arising in quantum affine Schur-Weyl duality. This allows us to expand the framework of KMS by Drinfeld twisting to introduce Gauss sums into the quantum wedge, which are necessary for connections to metaplectic forms. Our main theorem interprets the row transfer matrices of this ice model as “half” vertex operators on quantum Fock space that intertwine with the action of. In the process, we introduce new symmetric functions termedmetaplectic symmetric functionsand explain how they are related to Whittaker functions on ann-fold metaplectic cover of. These resembleLLT polynomialsorribbon symmetric functionsintroduced by Lascoux, Leclerc and Thibon, and in fact the metaplectic symmetric functions are (up to twisting) specializations ofsupersymmetric LLT polynomialsdefined by Lam. Indeed Lam constructed families of symmetric functions from Heisenberg algebra actions on the Fock space commuting with the-action. The Heisenberg algebra is independent of Drinfeld twisting of the quantum group. We explain that half vertex operators agree with Lam’s construction and this interpretation allows for many new identities for metaplectic symmetric and Whittaker functions, including Cauchy identities. While both metaplectic symmetric functions and LLT polynomials can be related to vertex operators on the quantum Fock space, only metaplectic symmetric functions are connected to solvable lattice models.