English

Log-majorizations between quasi-geometric type means for matrices

Functional Analysis 2026-01-21 v3 Quantum Physics

Abstract

In this paper, for α(0,){1}\alpha\in(0,\infty)\setminus\{1\}, p>0p>0 and positive semidefinite matrices AA and BB, we consider the quasi-extension Mα,p(A,B):=Mα(Ap,Bp)1/p\mathcal{M}_{\alpha,p}(A,B):=\mathcal{M}_\alpha(A^p,B^p)^{1/p} of several α\alpha-weighted geometric type matrix means Mα(A,B)\mathcal{M}_\alpha(A,B) such as the α\alpha-weighted geometric mean in Kubo--Ando's sense, the R\'enyi mean, etc. The log-majorization Mα,p(A,B)logNα,q(A,B)\mathcal{M}_{\alpha,p}(A,B)\prec_{\log}\mathcal{N}_{\alpha,q}(A,B) is examined for pairs (M,N)(\mathcal{M},\mathcal{N}) of those α\alpha-weighted geometric type means. The joint concavity/convexity of the trace functions TrMα,p\mathrm{Tr}\,\mathcal{M}_{\alpha,p} is also discussed based on theory of quantum divergences.

Keywords

Cite

@article{arxiv.2510.04691,
  title  = {Log-majorizations between quasi-geometric type means for matrices},
  author = {Fumio Hiai},
  journal= {arXiv preprint arXiv:2510.04691},
  year   = {2026}
}

Comments

44 pages, this includes the second half of the author's plenary talk in ILAS2025. Final print version

R2 v1 2026-07-01T06:18:52.473Z