Norm inequalities for submultiplicative functions involving contraction sector 2 × 2 $2 \times 2$ block matrices

Abstract

Abstract In this article, we show unitarily invariant norm inequalities for sector 2 × 2 $2\times 2$ block matrices which extend and refine some recent results of Bourahli, Hirzallah, and Kittaneh (Positivity, 2020, https://doi.org/10.1007/s11117-020-00770-w ).

Keywords

• Contraction sector block matrices
• Unitarily invariant norms
• Submultiplicative functions