Opuscula Math. 31, no. 3 (2011), 303-315
http://dx.doi.org/10.7494/OpMath.2011.31.3.303
Opuscula Mathematica
Investigating the numerical range and q-numerical range of non square matrices
Aikaterini Aretaki
John Maroulas
Abstract. A presentation of numerical ranges for rectangular matrices is undertaken in this paper, introducing two different definitions and elaborating basic properties. Further, we extend to the \(q\)-numerical range.
Keywords: numerical range, projectors, matrix norms, singular values.
Mathematics Subject Classification: 15A60, 15A18, 47A12, 47A30.
- Aikaterini Aretaki
- National Technical University of Athens, Department of Mathematics, Zografou Campus, 15780 Athens, Greece
- John Maroulas
- National Technical University of Athens, Department of Mathematics, Zografou Campus, 15780 Athens, Greece
- Received: 2010-09-03.
- Revised: 2010-10-18.
- Accepted: 2010-10-18.
