The Ratios between the Spectral Norm, the Numerical Radius and the Spectral Radius

Recently, Uhlig [Numer. Algorithms, 52(3):335-353, 2009] proposed open questions about the ratios between the spectral norm, the numerical radius and the spectral radius of a square matrix. In this note, we provide some observations to answer these questions.

• Kui Du

• Spectral norm
• Numerical radius
• Spectral radius
• Ratios

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