A subclass of the Cowen–Douglas class and similarity. Issue 11 (21st November 2022)

• Record Type: Journal Article
• Authors: Ji, Kui; Kwon, Hyun‐Kyoung; Sarkar, Jaydeb; Xu, Jing
• Is Part Of: Mathematische Nachrichten. Volume 295:Issue 11(2022)
• Page Start: 2197
• Page End: 2222
• Publication Date: 2022-11-21
• Subjects: Cowen–Douglas operator -- curvature -- eigenvector bundle -- holomorphic frame -- similarity; Mathematics -- Periodicals; 510.5
• DOI: 10.1002/mana.202000326
• Languages: English
• ISSNs: 0025-584X

Abstract

Abstract: We consider a subclass of the Cowen–Douglas class in which the problem of deciding whether two operators are similar becomes more manageable. A similarity criterion for Cowen–Douglas operators is known to be dependent on the trace of the curvature of the corresponding eigenvector bundles. Unless the given eignvector bundle is a line bundle, the computation of the curvature, in general, is not so simple as one might hope. By using a structure theorem on Cowen–Douglas operators, we reduce the problem of finding the trace of the curvature by looking at the curvatures of the associated line bundles. Several questions related to the similarity problem are also taken into account.