It is discussed the operator approach to systems with hysteresis. This
approach may be applied to various problems of magnetic media, plasti
sity, control theory, nonlinear oscillations, etc. It is considered th
e so-called vector model of magnetic hysteresis (I. Mayergoyz, G. Frie
dman) in an operator framework. It is discussed the phenomenon similar
to well-known Hopf bifurcation.