{ "id": "1007.3950", "version": "v4", "published": "2010-07-22T17:31:47.000Z", "updated": "2011-08-30T17:02:41.000Z", "title": "Degenerate two-boundary centralizer algebras", "authors": [ "Zajj Daugherty" ], "comment": "45 pages, to appear in Pacific Journal of Mathematics", "categories": [ "math.RT", "math.CO" ], "abstract": "Diagram algebras (e.g. graded braid groups, Hecke algebras, Brauer algebras) arise as tensor power centralizer algebras, algebras of commuting operators for a Lie algebra action on a tensor space. This work explores centralizers of the action of a complex reductive Lie algebra $\\mathfrak{g}$ on tensor space of the form $M \\otimes N \\otimes V^{\\otimes k}$. We define the degenerate two-boundary braid algebra $\\mathcal{G}_k$ and show that centralizer algebras contain quotients of this algebra in a general setting. As an example, we study in detail the combinatorics of special cases corresponding to Lie algebras $\\mathfrak{gl}_n$ and $\\mathfrak{sl}_n$ and modules $M$ and $N$ indexed by rectangular partitions. For this setting, we define the degenerate extended two-boundary Hecke algebra $\\mathcal{H}_k^{\\mathrm{ext}}$ as a quotient of $\\mathcal{G}_k$, and show that a quotient of $\\mathcal{H}_k^{\\mathrm{ext}}$ is isomorphic to a large subalgebra of the centralizer. We further study the representation theory of $\\mathcal{H}_k^{\\mathrm{ext}}$ to find that the seminormal representations are indexed by a known family of partitions. The bases for the resulting modules are given by paths in a lattice of partitions, and the action of $\\mathcal{H}_k^{\\mathrm{ext}}$ is given by combinatorial formulas.", "revisions": [ { "version": "v4", "updated": "2011-08-30T17:02:41.000Z" } ], "analyses": { "subjects": [ "20C08", "05E10", "17B10" ], "keywords": [ "degenerate two-boundary centralizer algebras", "tensor space", "degenerate two-boundary braid algebra", "tensor power centralizer algebras", "centralizer algebras contain quotients" ], "note": { "typesetting": "TeX", "pages": 45, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1007.3950D" } } }