Ela Numerical Ranges of Quadratic Operators in Spaces with an Indefinite Metric
نویسندگان
چکیده
The numerical range of a quadratic operator acting on an indefinite inner product space is shown to have a hyperbolical shape. This result is extended to different kinds of indefinite numerical ranges, namely, indefinite higher rank numerical ranges and indefinite Davis-Wielandt shells.
منابع مشابه
Numerical ranges of quadratic operators in spaces with an indefinte metric
The numerical range of a quadratic operator acting on an indefinite inner product space is shown to have a hyperbolical shape. This result is extended to different kinds of indefinite numerical ranges, namely, indefinite higher rank numerical ranges and indefinite Davis-Wielandt shells.
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