کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
757912 | 1462604 | 2016 | 22 صفحه PDF | دانلود رایگان |
• The modulation instability in a system of coupled Newell-Segel-Whitehead equations is studied. A phase amplitude ansatz approach is used to obtain its exact solutions. The bright-bright, dark-dark, bright-dark solitons are found.
By virtue of the modulational instability (MI) and phase amplitude ansatz approach, a system of coupled complex Newell–Segel–Whitehead equations (NSWEs), which describes isotropic systems near a subcritical oscillatory instability, is investigated. The constraints that allow the MI procedure to transform the system under consideration into a study of the roots of a polynomial equation of the fourth degree are obtained. A number of examples are analyzed graphically, to overcome the complexity of the dispersion relation and its dependence on many parameters. The existence of a variety of MI gain spectrum is observed. The influence of the cubic-quintic nonlinearity and the magnitude of the plane wave solutions of the system on the MI are also analyzed. Various novel solitary-wave solutions of the system, such as bright-bright, dark-dark, and dark-bright wave solutions, are analytically obtained using direct approach under some constraint conditions.
Journal: Communications in Nonlinear Science and Numerical Simulation - Volume 41, December 2016, Pages 118–139