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Indexed by:期刊论文

Date of Publication:2011-02-01

Journal:PROCEEDINGS OF THE AMERICAN MATHEMATICAL SOCIETY

Included Journals:Scopus、SCIE

Volume:139

Issue:2

Page Number:511-520

ISSN No.:0002-9939

Key Words:Index formula; two variable Jordan block; evaluation operator; Hardy space over bidisk

Abstract:On Hardy space H(2)(D(2)) over the bidisk, let (S(z), S(w)) be the compression of the pair (T(z), T(w)) to the quotient module H(2)(D(2)) circle minus M. In this paper, we obtain an index formula for (S(z), S(w)) when it is Fredholm. It is also shown that the evaluation operator L(0) is compact on a Beurling type quotient module if and only if the corresponding inner function is a finite Blaschke product in w.