Fiedler-Ando theorem for Ando-Li-Mathias mean of positive operators

Abstract

In this paper, we show several operator inequalities involving the Hadamard product and the Ando-Li-Mathias mean of $n$ positive operators on a Hilbert space, which are regarded as $n$-variable versions of the Fiedler-Ando theorem. As an application, we show an $n$-variable version of Fiedler type inequality via the Ando-Li-Mathias mean.