On the geometry of numerical ranges in spaces with an indefinite inner product

• Author(s): Bebiano, N. ; Lemos, R. ; Providência, J. da ; Soares, G.
• Date: 2005
• Persistent ID: http://hdl.handle.net/10316/4632
• Origin: Estudo Geral - Universidade de Coimbra
• Subject(s): Indefinite inner product; Numerical range; Generalized Levinger curve
• Document Type: Article
• Language: English

Description

Geometric properties of the numerical ranges of operators on an indefinite inner product space are investigated. In particular, classes of matrices are presented such that the boundary generating curves of the J-numerical range are hyperbolical. The curvature of the J-numerical range at a boundary point is studied, generalizing results of Fiedler on the classical numerical range. http://www.sciencedirect.com/science/article/B6V0R-4CS4S2Y-3/1/7cad13ced1ef55f0c600d1ffdb4ec365