The Dunkl weight function for rational Cherednik algebras

Abstract In this paper we prove the existence of the Dunkl weight function $$K_{c, \lambda }$$Kc,λ for any irreducible representation $$\lambda $$λ of any finite Coxeter group W, generalizing previous results of Dunkl. In particular, $$K_{c, \lambda }$$Kc,λ is a family of tempered distributions on...

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Main Author: Shelley-Abrahamson, Seth
Other Authors: Massachusetts Institute of Technology. Department of Mathematics
Format: Article
Language:English
Published: Springer International Publishing 2021
Online Access:https://hdl.handle.net/1721.1/131366
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author Shelley-Abrahamson, Seth
author2 Massachusetts Institute of Technology. Department of Mathematics
author_facet Massachusetts Institute of Technology. Department of Mathematics
Shelley-Abrahamson, Seth
author_sort Shelley-Abrahamson, Seth
collection MIT
description Abstract In this paper we prove the existence of the Dunkl weight function $$K_{c, \lambda }$$Kc,λ for any irreducible representation $$\lambda $$λ of any finite Coxeter group W, generalizing previous results of Dunkl. In particular, $$K_{c, \lambda }$$Kc,λ is a family of tempered distributions on the real reflection representation of W taking values in $$\text {End}_\mathbb {C}(\lambda )$$EndC(λ), with holomorphic dependence on the complex multi-parameter c. When the parameter c is real, the distribution $$K_{c, \lambda }$$Kc,λ provides an integral formula for Cherednik’s Gaussian inner product $$\gamma _{c, \lambda }$$γc,λ on the Verma module $$\Delta _c(\lambda )$$Δc(λ) for the rational Cherednik algebra $$H_c(W, \mathfrak {h})$$Hc(W,h).queryPlease check and confirm the inserted city name ‘Stanford’ for the affiliation is correct. In this case, the restriction of $$K_{c, \lambda }$$Kc,λ to the hyperplane arrangement complement $$\mathfrak {h}_{\mathbb {R}, reg}$$hR,reg is given by integration against an analytic function whose values can be interpreted as braid group invariant Hermitian forms on $$KZ(\Delta _c(\lambda ))$$KZ(Δc(λ)), where KZ denotes the Knizhnik–Zamolodchikov functor introduced by Ginzburg–Guay–Opdam–Rouquier. This provides a concrete connection between invariant Hermitian forms on representations of rational Cherednik algebras and invariant Hermitian forms on representations of Iwahori–Hecke algebras, and we exploit this connection to show that the KZ functor preserves signatures, and in particular unitarizability, in an appropriate sense.
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spelling mit-1721.1/1313662023-12-22T20:32:05Z The Dunkl weight function for rational Cherednik algebras Shelley-Abrahamson, Seth Massachusetts Institute of Technology. Department of Mathematics Abstract In this paper we prove the existence of the Dunkl weight function $$K_{c, \lambda }$$Kc,λ for any irreducible representation $$\lambda $$λ of any finite Coxeter group W, generalizing previous results of Dunkl. In particular, $$K_{c, \lambda }$$Kc,λ is a family of tempered distributions on the real reflection representation of W taking values in $$\text {End}_\mathbb {C}(\lambda )$$EndC(λ), with holomorphic dependence on the complex multi-parameter c. When the parameter c is real, the distribution $$K_{c, \lambda }$$Kc,λ provides an integral formula for Cherednik’s Gaussian inner product $$\gamma _{c, \lambda }$$γc,λ on the Verma module $$\Delta _c(\lambda )$$Δc(λ) for the rational Cherednik algebra $$H_c(W, \mathfrak {h})$$Hc(W,h).queryPlease check and confirm the inserted city name ‘Stanford’ for the affiliation is correct. In this case, the restriction of $$K_{c, \lambda }$$Kc,λ to the hyperplane arrangement complement $$\mathfrak {h}_{\mathbb {R}, reg}$$hR,reg is given by integration against an analytic function whose values can be interpreted as braid group invariant Hermitian forms on $$KZ(\Delta _c(\lambda ))$$KZ(Δc(λ)), where KZ denotes the Knizhnik–Zamolodchikov functor introduced by Ginzburg–Guay–Opdam–Rouquier. This provides a concrete connection between invariant Hermitian forms on representations of rational Cherednik algebras and invariant Hermitian forms on representations of Iwahori–Hecke algebras, and we exploit this connection to show that the KZ functor preserves signatures, and in particular unitarizability, in an appropriate sense. 2021-09-20T17:16:45Z 2021-09-20T17:16:45Z 2020-01-18 2020-09-24T21:11:34Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/131366 Selecta Mathematica. 2020 Jan 18;26(1):8 en https://doi.org/10.1007/s00029-019-0533-4 Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. Springer Nature Switzerland AG application/pdf Springer International Publishing Springer International Publishing
spellingShingle Shelley-Abrahamson, Seth
The Dunkl weight function for rational Cherednik algebras
title The Dunkl weight function for rational Cherednik algebras
title_full The Dunkl weight function for rational Cherednik algebras
title_fullStr The Dunkl weight function for rational Cherednik algebras
title_full_unstemmed The Dunkl weight function for rational Cherednik algebras
title_short The Dunkl weight function for rational Cherednik algebras
title_sort dunkl weight function for rational cherednik algebras
url https://hdl.handle.net/1721.1/131366
work_keys_str_mv AT shelleyabrahamsonseth thedunklweightfunctionforrationalcherednikalgebras
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