Various inequalities between quasi-arithmetic mean and quasi-geometric type means for matrices

In this paper, for $0<α<1$, $p>0$ and positive semidefinite matrices A,B≥0, we consider the quasi-extension \[ α,p(A,B):=((1-α)A^p+αB^p)1/p \] of the $α$-weighted arithmetic matrix mean, and the quasi-extensions \[ α,p(A,B):=_α(A^p,B^p)1/p \] of several different $α$-weighted geometric-type matrix means _α(A,B) such as the $α$-weighted geometric mean in Kubo and Ando's sense and two types of $α$-weighted version of the spectral geometric mean due to Fiedler and Pták, as well as the Rényi mean and the $α$-weighted Log-Euclidean mean. For these we examine the inequalities α,p(A,B)α,q(A,B) and α,p(A,B)α,q(A,B) of arithmetic-geometric type, where is one of several different matrix orderings varying from the strongest Loewner order to the weakest order determined by trace inequality. For each choice of the above inequalities, our goal is to hopefully obtain the necessary and sufficient condition on $p,q,α$ under which the inequality holds for all A,B≥0.