{ "id": "2002.01298", "version": "v1", "published": "2020-02-04T14:26:13.000Z", "updated": "2020-02-04T14:26:13.000Z", "title": "$\\mathbb K$-homogeneous tuple of operators on bounded symmetric domains", "authors": [ "Soumitra Ghara", "Surjit Kumar", "Paramita Pramanick" ], "comment": "17 pages", "categories": [ "math.FA" ], "abstract": "Let $\\Omega$ be an irreducible bounded symmetric domain of rank $r$ in $\\mathbb C^d.$ Let $\\mathbb K$ be the maximal compact subgroup of the identity component $G$ of the biholomorphic automorphism group of the domain $\\Omega$. The group $\\mathbb K$ consisting of linear transformations acts naturally on any $d$-tuple $\\boldsymbol T=(T_1,\\ldots, T_d)$ of commuting bounded linear operators. If the orbit of this action modulo unitary equivalence is a singleton, then we say that $\\boldsymbol T$ is $\\mathbb{K}$-homogeneous. In this paper, we obtain a model for all $\\mathbb{K}$-homogeneous $d$-tuple $\\boldsymbol{T}$ as the operators of multiplication by the coordinate functions $z_1,\\ldots ,z_d$ on a reproducing kernel Hilbert space of holomorphic functions defined on $\\Omega$. Using this model we obtain a criterion for (i) boundedness, (ii) membership in the Cowen-Douglas class (iii) unitary equivalence and similarity of these $d$-tuples. In particular, we show that the adjoint of the $d$-tuple of multiplication by the coordinate functions on the weighted Bergman spaces are in the Cowen-Douglas class $B_1(\\Omega)$. For a bounded symmetric domain $\\Omega$ of rank $2$, an explicit description of the operator $\\sum_{i=1}^d T_i^*T_i$ is given. In general, based on this formula, we make a conjecture giving the form of this operator.", "revisions": [ { "version": "v1", "updated": "2020-02-04T14:26:13.000Z" } ], "analyses": { "keywords": [ "bounded symmetric domain", "homogeneous tuple", "cowen-douglas class", "coordinate functions", "action modulo unitary equivalence" ], "note": { "typesetting": "TeX", "pages": 17, "language": "en", "license": "arXiv", "status": "editable" } } }