Functional analysis
Flag structure for operators in the Cowen–Douglas class
Comptes Rendus. Mathématique, Tome 352 (2014) no. 6, pp. 511-514.

La description explicite des opérateurs homogènes et la localisation d'un module de Hilbert conduit naturellement à la définition d'une classe d'opérateurs de Cowen–Douglas possédant une structure flag. Ces opérateurs sont irréductibles. Nous montrons que la structure flag est rigide en ce sens que la classe d'équivalence unitaire de l'opérateur et la structure du pavillon se déterminent l'une l'autre. Nous obtenons un ensemble complet d'invariants unitaires qui sont un peu plus dociles que ceux d'un opérateur arbitraire dans la classe de Cowen–Douglas.

The explicit description of homogeneous operators and localization of a Hilbert module naturally leads to the definition of a class of Cowen–Douglas operators possessing a flag structure. These operators are irreducible. We show that the flag structure is rigid in the sense that the unitary equivalence class of the operator and the flag structure determine each other. We obtain a complete set of unitary invariants which are somewhat more tractable than those of an arbitrary operator in the Cowen–Douglas class.

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DOI : 10.1016/j.crma.2014.04.001
Ji, Kui 1 ; Jiang, Chunlan 1 ; Keshari, Dinesh Kumar 2 ; Misra, Gadadhar 3

1 Department of Mathematics, Hebei Normal University, Shijiazhuang, Hebei 050016, China
2 Department of Mathematics, Texas A&M University, College Station, TX 77843, United States
3 Department of Mathematics, Indian Institute of Science, Bangalore 560 012, India
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Ji, Kui; Jiang, Chunlan; Keshari, Dinesh Kumar; Misra, Gadadhar. Flag structure for operators in the Cowen–Douglas class. Comptes Rendus. Mathématique, Tome 352 (2014) no. 6, pp. 511-514. doi : 10.1016/j.crma.2014.04.001. http://www.numdam.org/articles/10.1016/j.crma.2014.04.001/

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