English

Some extensions of the Young and Heinz inequalities for Matrices

Functional Analysis 2017-05-09 v1

Abstract

In this paper, we present some extensions of the Young and Heinz inequalities for the Hilbert-Schmidt norm as well as any unitarily invariant norm. Furthermore, we give some inequalities dealing with matrices. More precisely, for two positive semidefinite matrices AA and BB we show that \begin{align*} \Big\|A^{\nu}XB^{1-\nu}+A^{1-\nu}XB^{\nu}\Big\|_{2}^{2}\leq\Big\|AX+XB\Big\|_{2}^{2}- 2r\Big\|AX-XB\Big\|_{2}^{2}-r_{0}\left(\Big\|A^{\frac{1}{2}}XB^{\frac{1}{2}}-AX\Big\|_{2}^{2}+ \Big\|A^{\frac{1}{2}}XB^{\frac{1}{2}}-XB\Big\|_{2}^{2}\right), \end{align*} where XX is an arbitrary n×nn\times n matrix, 0<ν120<\nu\leq\frac{1}{2}, r=min{ν,1ν}r=\min\{\nu, 1-\nu\} and r0=min{2r,12r}r_{0}=\min\{2r, 1-2r\}.

Keywords

Cite

@article{arxiv.1705.02585,
  title  = {Some extensions of the Young and Heinz inequalities for Matrices},
  author = {Monire Hajmohamadi and Rahmatollah Lashkaripour and Mojtaba Bakherad},
  journal= {arXiv preprint arXiv:1705.02585},
  year   = {2017}
}