Tensorial and Hadamard product inequalities for functions of selfadjoint operators in Hilbert spaces in terms of Kantorovich ratio

Autores/as

  • S.S. Dragomir Mathematics, College of Engineering & Science Victoria University, PO Box 14428, Melbourne City 8001, Australia

DOI:

https://doi.org/10.17398/2605-5686.38.2.237

Palabras clave:

Tensorial product, Hadamard Product, Selfadjoint operators, Convex functions

Resumen

Let H be a Hilbert space. In this paper we show among others that, if f, g are continuous on the interval I with

0 <γ ≤ f(t)/g(t)≤ Γ    for t ∈ I

and if A and B are selfadjoint operators with Sp (A), Sp (B) ⊂ I, then


[f1−ν(A) gν (A)] ⊗ [fν(B) g1−ν (B)]  ≤ (1 − ν) f (A) ⊗ g (B) + ν g (A) ⊗ f (B)
                    ≤ [(γ + Γ) 2/4γΓ]R [f1−ν(A) gν (A)] ⊗ [fν(B) g1−ν (B)]. 

The above inequalities also hold for the Hadamard product “ ◦ ” instead of tensorial product “ ⊗ ”.

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Referencias

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Publicado

2023-12-01

Número

Sección

Operator Theory

Cómo citar

Tensorial and Hadamard product inequalities for functions of selfadjoint operators in Hilbert spaces in terms of Kantorovich ratio. (2023). Extracta Mathematicae, 38(2), 237-250. https://doi.org/10.17398/2605-5686.38.2.237