Johnny Henderson

The mathematical modeling of many problems from economics, computer science, engineering, biological neural networks and others leads to the consideration of nonlinear difference equations. Many authors have studied such problems by using various methods, such as: the fixed point theory, the fixed point index theory, variational methods, the critical point theory, different transformations, extensions of Perron's second theorem, diversified criteria for the stability of solutions, and so on. This monograph studies the existence of positive solutions for some classes of second-order nonlinear finite difference equations, and systems of second-order nonlinear finite difference equations, subject to various multi-point boundary conditions. In the case of systems, these boundary conditions may be uncoupled or coupled. It also investigates a class of nonlinear ??th order Atici-Eloe fractional difference equations supplemented with varied boundary conditions, and some systems of generalized second-order difference equations in Hilbert spaces with multi-point boundary conditions. The book draws together our results that have been obtained in the last years. Chapter 1 deals with the existence of positive solutions for two second-order finite difference equations which contain a linear term and a sign-changing nonlinearity, with or without parameters, subject to multi-point boundary conditions. Chapter 2 is focused on the existence and multiplicity of positive solutions for two systems of nonlinear second-order difference equations with uncoupled multi-point boundary conditions. The nonlinearities from the systems are nonnegative functions and satisfy some assumptions containing concave functions, or they are sign-changing functions. Chapter 3 studies the existence and nonexistence of positive solutions for two systems of nonlinear second-order difference equations supplemented with coupled multi-point boundary conditions, with positive parameters in the systems or in the boundary conditions. The nonlinearities of the systems are nonnegative functions and satisfy various assumptions. Chapter 4 is concerned with the existence and multiplicity of positive solutions for two systems of nonlinear second-order difference equations subject to coupled multi-point boundary conditions, without parameters. The nonlinearities of the systems are nonnegative functions and satisfy various assumptions. Chapter 5 is devoted to the existence of positive solutions for a system of nonlinear second-order difference equations with parameters and sign-changing nonlinearities, supplemented with multi-point coupled boundary conditions. Chapter 6 deals with the existence of nontrivial solutions, nonnegative solutions and positive solutions for a class of nonlinear ??th order Atici-Eloe fractional difference equations with left focal boundary conditions or Dirichlet boundary conditions. In each chapter, various examples are presented which support the main results. Finally, the new Chapter 7 investigates the existence and uniqueness of solutions for some nonlinear systems of generalized second-order difference equations in Hilbert spaces, subject to multi-point boundary conditions containing monotone operators. Some applications to initial-boundary value problems for nonlinear first-order differential systems with monotone operators are also addressed. The methods used in the proof of our theorems include results from the fixed point theory, the fixed point index theory, the theory of monotone operators and nonlinear evolution equations of monotone type in Hilbert spaces. This monograph can serve as a good resource for the mathematical and scientific researchers, and for the graduate students in mathematics and science interested in the existence of solutions and positive solutions for finite difference equations and systems.

Johnny Henderson spent four years during the Second World War as aide-de-camp to one of Britain’s most famous soldiers of the twentieth century, General Bernard Montgomery – or ‘Monty’, as he was popularly known. Shortly before he died in 2003, Henderson wrote about his time with Monty at Tac HQ.In Watching Monty, his account takes the form of a series of insightful anecdotes and brief pen sketches that give a fascinating and often humorous window on life with Monty and those with whom he worked, or came into contact, during the war years. These people range from King George VI, Winston Churchill and Sir Alan Brooke to Eisenhower and the German surrender delegation on Lüneburg Heath.Drawing on his own private photograph albums and the photographic collections of the Imperial War Museum, Johnny Henderson relates his time as Monty’s ADC, from the Western Desert to Berlin, in the form of a photographic anecdotal scrap book. His pithy observations of life at Tac HQ make a unique contribution to our understanding of what made Monty tick, and shows us a less well-known but lighter side of the great man.

This is an indispensable reference for those mathematicians that conduct research activity in applications of fixed-point theory to boundary value problems for nonlinear difference equations. Coverage includes second-order finite difference equations and systems of second-order finite difference equations subject to diverse multi-point boundary conditions, and various methods to study the existence of positive solutions for these problems.

Topological Methods for Differential Equations and Inclusions covers the important topics involving topological methods in the theory of systems of differential equations. The equivalence between a control system and the corresponding differential inclusion is the central idea used to prove existence theorems in optimal control theory. Since the dynamics of economic, social, and biological systems are multi-valued, differential inclusions serve as natural models in macro systems with hysteresis.

This book deals with the existence and stability of solutions to initial and boundary value problems for functional differential and integral equations and inclusions involving the Riemann-Liouville, Caputo, and Hadamard fractional derivatives and integrals. A wide variety of topics is covered in a mathematically rigorous manner making this work a valuable source of information for graduate students and researchers working with problems in fractional calculus. ContentsPreliminary Background Nonlinear Implicit Fractional Differential Equations Impulsive Nonlinear Implicit Fractional Differential Equations Boundary Value Problems for Nonlinear Implicit Fractional Differential Equations Boundary Value Problems for Impulsive NIFDE Integrable Solutions for Implicit Fractional Differential Equations Partial Hadamard Fractional Integral Equations and Inclusions Stability Results for Partial Hadamard Fractional Integral Equations and Inclusions Hadamard–Stieltjes Fractional Integral Equations Ulam Stabilities for Random Hadamard Fractional Integral Equations

Boundary Value Problems for Systems of Differential, Difference and Fractional Equations: Positive Solutions discusses the concept of a differential equation that brings together a set of additional constraints called the boundary conditions. As boundary value problems arise in several branches of math given the fact that any physical differential equation will have them, this book will provide a timely presentation on the topic. Problems involving the wave equation, such as the determination of normal modes, are often stated as boundary value problems. To be useful in applications, a boundary value problem should be well posed. This means that given the input to the problem there exists a unique solution, which depends continuously on the input. Much theoretical work in the field of partial differential equations is devoted to proving that boundary value problems arising from scientific and engineering applications are in fact well-posed.

Differential equations with impulses arise as models of many evolving processes that are subject to abrupt changes, such as shocks, harvesting, and natural disasters. These phenomena involve short-term perturbations from continuous and smooth dynamics, whose duration is negligible in comparison with the duration of an entire evolution. In models involving such perturbations, it is natural to assume these perturbations act instantaneously or in the form of impulses. As a consequence, impulsive differential equations have been developed in modeling impulsive problems in physics, population dynamics, ecology, biotechnology, industrial robotics, pharmacokinetics, optimal control, and so forth. There are also many different studies in biology and medicine for which impulsive differential equations provide good models. During the last 10 years, the authors have been responsible for extensive contributions to the literature on impulsive differential inclusions via fixed point methods. This book is motivated by that research as the authors endeavor to bring under one cover much of those results along with results by other researchers either affecting or affected by the authors' work. The questions of existence and stability of solutions for different classes of initial value problems for impulsive differential equations and inclusions with fixed and variable moments are considered in detail. Attention is also given to boundary value problems. In addition, since differential equations can be viewed as special cases of differential inclusions, significant attention is also given to relative questions concerning differential equations. This monograph addresses a variety of side issues that arise from its simpler beginnings as well.