The nonlinear sciences have been taking new dimensions with the passage of time. The through study of the literature witnesses the introduction of a number of new techniques which are being used to cope with the versatility of diversified physical problems, and in the same context, a number of numerical and analytical techniques have been developed to cope with the physical nature of such equations. The basic purpose of this special issue is to extend the applications of the relatively new approaches and theories for nonlinear problems of physical nature arising in mathematics, physics, and applied sciences and would see the latest developments in the same context. The authors are invited to submit original research articles as well as review articles that will stimulate the continuing efforts in nonlinear equations and related theories. The special issue will provide a forum for researches and scientists to communicate their recent developments and to present their novel results on nonlinear equations and related problems. Potential topics include, but are not limited to:

• Solitary wave theory
• Solitons and compactons
• Geometric function theory and its applications
• Symmetries and separation of variables
• Hirota's bilinear method
• Painlevé test and analysis
• Hamilton-Jacobi approach
• Variational inequalities and their applications
• Analytical methods such as variational iteration techniques and its various modifications
• Variation of parameters method
• Continuous and discrete integrable equations
• Numerical approaches to nonlinear waves
• Stability theory of solitary waves

Before submission authors should carefully read over the journal's Author Guidelines, which are located at http://www.hindawi.com/journals/aaa/guidelines/. Prospective authors should submit an electronic copy of their complete manuscript through the journal Manuscript Tracking System at http://mts.hindawi.com/ according to the following timetable: