Self-consistent magnetic dynamic susceptibility in the itinerant magnets*

We propose a linear response approach for studying magnetic excitations in itinerant magnets using spin dynamic susceptibility. The method is self-consistent and based on the Mori correlation function theory. The self-consistency is obtained directly using corresponding spin-spin current and spin current-spin current correlators. With such approach no introduction of any enhancement factor aka Stoner parameter is needed. We discuss the advantages of such an approach relative to traditional standard linear response schemes. The density functional studies of magnetic excitations in 3d metals will be presented and compared with earlier results.