On variational methods for nonlinear difference equations

global results on some nonlinear partial differential equations for direct and inverse problems

در این رساله به بررسی رفتار جواب های رده ای از معادلات دیفرانسیل با مشتقات جزیی در دامنه های کراندار می پردازیم . این معادلات به فرم نیم-خطی و غیر خطی برای مسایل مستقیم و معکوس مورد مطالعه قرار می گیرند . به ویژه، تاثیر شرایط مختلف فیزیکی را در مساله، نظیر وجود موانع و منابع، پراکندگی و چسبندگی در معادلات موج و گرما بررسی می کنیم و به دنبال شرایطی می گردیم که متضمن وجود سراسری یا عدم وجود سراسر...

On Exponential Dichotomy of Variational Difference Equations

On Exponential Stability of Variational Difference Equations

We prove that a general system of variational difference equations is uniformly exponentially stable if and only if certain associated sets are of the second category. We also deduce necessary and sufficient conditions for uniform exponential stability of systems with uniformly bounded coefficients. We apply our results for the study of exponential stability of linear skew-product flows, genera...

Projected Equations, Variational Inequalities, and Temporal Difference Methods

We consider projected equations for approximate solution of high-dimensional fixed point problems within lowdimensional subspaces. We introduce an analytical framework based on an equivalence with variational inequalities (VIs), and a class of iterative feasible direction methods that may be implemented with low-dimensional simulation. These methods originated in approximate dynamic programming...

Difference Methods for Nonlinear First-Order Hyperbolic Systems of Equations

Two difference methods for approximating some first-order nonlinear hyperbolic differential equations are considered. The methods apply to problems arising in a number of physical applications. Each of the methods is explicit and can be implemented on a computer easily. It is proved that the methods are first-order convergent in the maximum norm. For one of the methods in order to obtain conver...