|
The Vakhitov–Kolokolov stability criterion is a condition for linear stability (sometimes called ''spectral stability'') of solitary wave solutions to a wide class of U(1)-invariant Hamiltonian systems, named after Russian scientists Aleksandr Kolokolov (Александр Александрович Колоколов) and Nazib Vakhitov (Назиб Галиевич Вахитов). The condition for linear stability of a solitary wave with frequency has the form : where is the charge (or momentum) of the solitary wave , conserved by Noether's theorem due to U(1)-invariance of the system. ==Original formulation== Originally, this criterion was obtained for the nonlinear Schrödinger equation, : where , , and is a smooth real-valued function. The solution is assumed to be complex-valued. Since the equation is U(1)-invariant, by Noether's theorem, it has an integral of motion, , which is called charge or momentum, depending on the model under consideration. For a wide class of functions , the nonlinear Schrödinger equation admits solitary wave solutions of the form , where and decays for large (one often requires that belongs to the Sobolev space ). Usually such solutions exist for from an interval or collection of intervals of a real line. Vakhitov–Kolokolov stability criterion, : is a condition of spectral stability of a solitary wave solution. Namely, if this condition is satisfied at a particular value of , then the linearization at the solitary wave with this has no spectrum in the right half-plane. This result is based on an earlier work by Vladimir Zakharov. 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Vakhitov–Kolokolov stability criterion」の詳細全文を読む スポンサード リンク
|