Přehled o publikaci

In this article, we obtain two sets of results. The first set of results are for the case of the bi-disc while the second set of results describe in part, which of these carry over to the general case of the poly-disc. A classification of irreducible hermitian holomorphic vector bundles over D-2, homogeneous with respect to Mob x Mob, is obtained assuming that the associated representations are multiplicity-free. Among these the ones that give rise to an operator in the Cowen-Douglas class of D-2 of rank 1, 2 or 3 are determined. Any hermitian holomorphic vector bundle of rank 2 over D-n, homogeneous with respect to the n-fold direct product of the group Mob is shown to be a tensor product of n hermitian holomorphic vector bundles over D. Among them, n - 1 are shown to be the line bundles and one is shown to be a rank 2 bundle. Also, each of the bundles are homogeneous with respect to Mob. The classification of irreducible homogeneous hermitian holomorphic vector bundles over D-2 of rank 3 (as well as the corresponding Cowen-Douglas class of operators) is extended to the case of D-n, n > 2. It is shown that there is no irreducible n - tuple of operators in the Cowen-Douglas class B-2 (D-n) that is homogeneous with respect to Aut(D-n), n > 1. Also, pairs of operators in B-3(D-2) homogeneous with respect to Aut(D-2) are produced, while it is shown that no n - tuple of operators in B-3(D-n) is homogeneous with respect to Aut(D-n), n > 2.