English

Some inequalities for interpolational operator means

Functional Analysis 2018-08-28 v1

Abstract

Using the properties of geometric mean, we shall show for any 0α,β10\le \alpha ,\beta \le 1, f(AαB)f((AαB)βA)αf((AαB)βB)f(A)αf(B)f\left( A{{\nabla }_{\alpha }}B \right)\le f\left( \left( A{{\nabla }_{\alpha }}B \right){{\nabla }_{\beta }}A \right){{\sharp}_{\alpha }}f\left( \left( A{{\nabla }_{\alpha }}B \right){{\nabla }_{\beta }}B \right)\le f\left( A \right){{\sharp}_{\alpha }}f\left( B \right) whenever ff is a non-negative operator log-convex function, A,BB(H)A,B\in \mathcal{B}\left( \mathcal{H} \right) are positive operators, and 0α,β10\le \alpha ,\beta \le 1. As an application of this operator mean inequality, we present several refinements of the Aujla subadditive inequality for operator monotone decreasing functions. Also, in a similar way, we consider some inequalities of Ando's type. Among other things, it is shown that if Φ\Phi is a positive linear map, then Φ(AαB)Φ((AαB)βA)αΦ((AαB)βB)Φ(A)αΦ(B).\Phi \left( A{{\sharp}_{\alpha }}B \right)\le \Phi \left( \left( A{{\sharp}_{\alpha }}B \right){{\sharp}_{\beta }}A \right){{\sharp}_{\alpha }}\Phi \left( \left( A{{\sharp}_{\alpha }}B \right){{\sharp}_{\beta }}B \right)\le \Phi \left( A \right){{\sharp}_{\alpha }}\Phi \left( B \right).

Keywords

Cite

@article{arxiv.1808.08342,
  title  = {Some inequalities for interpolational operator means},
  author = {Hamid Reza Moradi and Shigeru Furuichi and Mohammad Sababheh},
  journal= {arXiv preprint arXiv:1808.08342},
  year   = {2018}
}

Comments

9 pages

R2 v1 2026-06-23T03:43:28.721Z