English

$\mathbb K$-homogeneous tuple of operators on bounded symmetric domains

Functional Analysis 2020-02-05 v1

Abstract

Let Ω\Omega be an irreducible bounded symmetric domain of rank rr in Cd.\mathbb C^d. Let K\mathbb K be the maximal compact subgroup of the identity component GG of the biholomorphic automorphism group of the domain Ω\Omega. The group K\mathbb K consisting of linear transformations acts naturally on any dd-tuple T=(T1,,Td)\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 T\boldsymbol T is K\mathbb{K}-homogeneous. In this paper, we obtain a model for all K\mathbb{K}-homogeneous dd-tuple T\boldsymbol{T} as the operators of multiplication by the coordinate functions z1,,zdz_1,\ldots ,z_d on a reproducing kernel Hilbert space of holomorphic functions defined on Ω\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 dd-tuples. In particular, we show that the adjoint of the dd-tuple of multiplication by the coordinate functions on the weighted Bergman spaces are in the Cowen-Douglas class B1(Ω)B_1(\Omega). For a bounded symmetric domain Ω\Omega of rank 22, an explicit description of the operator i=1dTiTi\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.

Keywords

Cite

@article{arxiv.2002.01298,
  title  = {$\mathbb K$-homogeneous tuple of operators on bounded symmetric domains},
  author = {Soumitra Ghara and Surjit Kumar and Paramita Pramanick},
  journal= {arXiv preprint arXiv:2002.01298},
  year   = {2020}
}

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17 pages