English

Some inequalities for the matrix Heron mean

Functional Analysis 2016-05-12 v1 Operator Algebras

Abstract

Let A,BA, B be positive definite matrices, p=1,2p=1, 2 and r0r\ge 0. It is shown that \begin{equation*} ||A+ B + r(A\sharp_t B+A\sharp_{1-t} B)||_p \le ||A+ B + r(A^{t}B^{1-t} + A^{1-t}B^t)||_p. \end{equation*} We also prove that for positive definite matrices AA and BB \begin{equation*}\label{det} \Dt (P_{t}(A, B)) \le \Dt (Q_{t}(A, B)), \end{equation*} where Qt(A,B)=(At+Bt2)1/tQ_t(A, B)= \big(\frac{A^t+B^t}{2}\big)^{1/t} and Pt(A,B)P_t(A, B) is the tt-power mean of AA and BB. As a consequence, we obtain the determinant inequality for the matrix Heron mean: for any positive definite matrices AA and B,B, \Dt(A+B+2(AB))\Dt(A+B+A1/2B1/2+A1/2B1/2)). \Dt(A+ B + 2(A\sharp B)) \le \Dt(A+ B + A^{1/2}B^{1/2} + A^{1/2}B^{1/2})). These results complement those obtained by Bhatia, Lim and Yamazaki (LAA, {\bf 501} (2016) 112-122).

Keywords

Cite

@article{arxiv.1605.03516,
  title  = {Some inequalities for the matrix Heron mean},
  author = {Dinh Trung Hoa},
  journal= {arXiv preprint arXiv:1605.03516},
  year   = {2016}
}

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R2 v1 2026-06-22T13:58:40.597Z