Operator arithmetic-harmonic mean inequality on Krein spaces

چکیده مقاله

We prove an operator arithmetic-harmonic mean type in-equality in Krein space setting, by using some block matrix techniquesof indefinite type. We also give an example which shows that the oper-ator arithmetic-geometric-harmonic mean inequality for two invertibleselfadjoint operators on Krein spaces is not valid, in general.