Author	Verhulst, Ferdinand. author
Title	Nonlinear Differential Equations and Dynamical Systems [electronic resource] / by Ferdinand Verhulst
Imprint	Berlin, Heidelberg : Springer Berlin Heidelberg, 1990
Connect to	http://dx.doi.org/10.1007/978-3-642-97149-5
Descript	IX, 277 p. online resource

On the subject of differential equations a great many elementary books have been written. This book bridges the gap between elementary courses and the research literature. The basic concepts necessary to study differential equations - critical points and equilibrium, periodic solutions, invariant sets and invariant manifolds - are discussed. Stability theory is developed starting with linearisation methods going back to Lyapunov and Poincarรฉ. The global direct method is then discussed. To obtain more quantitative information the Poincarรฉ-Lindstedt method is introduced to approximate periodic solutions while at the same time proving existence by the implicit function theorem. The method of averaging is introduced as a general approximation-normalisation method. The last four chapters introduce the reader to relaxation oscillations, bifurcation theory, centre manifolds, chaos in mappings and differential equations, Hamiltonian systems (recurrence, invariant tori, periodic solutions). The book presents the subject material from both the qualitative and the quantitative point of view. There are many examples to illustrate the theory and the reader should be able to start doing research after studying this book

1 Introduction -- 1.1 Definitions and notation -- 1.2 Existence and uniqueness -- 1.3 Gronwallโ{128}{153}s inequality -- 2 Autonomous equations -- 2.1 Phase-space, orbits -- 2.2 Critical points and linearisation -- 2.3 Periodic solutions -- 2.4 First integrals and integral manifolds -- 2.5 Evolution of a volume element, Liouvilleโ{128}{153}s theorem -- 2.6 Exercises -- 3 Critical points -- 3.1 Two-dimensional linear systems -- 3.2 Remarks on three-dimensional linear systems -- 3.3 Critical points of nonlinear equations -- 3.4 Exercises -- 4 Periodic solutions -- 4.1 Bendixsonโ{128}{153}s criterion -- 4.2 Geometric auxiliaries, preparation for the Poincarรฉ- Bendixson theorem -- 4.3 The Poincarรฉ-Bendixson theorem -- 4.4 Applications of the Poincarรฉ-Bendixson theorem -- 4.5 Periodic solutions in Rn. -- 4.6 Exercises -- 5 Introduction to the theory of stability -- 5.1 Simple examples -- 5.2 Stability of equilibrium solutions -- 5.3 Stability of periodic solutions -- 5.4 Linearisation -- 5.5 Exercises -- 6 Linear equations -- 6.1 Equations with constant coefficients -- 6.2 Equations with coefficients which have a limit -- 6.3 Equations with periodic coefficients -- 6.4 Exercises -- 7 Stability by linearisation -- 7.1 Asymptotic stability of the trivial solution -- 7.2 Instability of the trivial solution -- 7.3 Stability of periodic solutions of autonomous equations -- 7.4 Exercises -- 8 Stability analysis by the direct method -- 8.1 Introduction -- 8.2 Lyapunov functions -- 8.3 Hamiltonian systems and systems with first integrals -- 8.4 Applications and examples -- 8.5 Exercises -- 9 Introduction to perturbation theory -- 9.1 Background and elementary examples -- 9.2 Basic material -- 9.3 Naรฏve expansion -- 9.4 The Poincarรฉ expansion theorem -- 9.5 Exercises -- 10 The Poincarรฉ-Lindstedt method -- 10.1 Periodic solutions of autonomous second-order equations -- 10.2 Approximation of periodic solutions on arbitrary long time-scales -- 10.3 Periodic solutions of equations with forcing terms -- 10.4 The existence of periodic solutions -- 10.5 Exercises -- 11 The method of averaging -- 11.1 Introduction -- 11.2 The Lagrange standard form -- 11.3 Averaging in the periodic case -- 11.4 Averaging in the general case -- 11.5 Adiabatic invariants -- 11.6 Averaging over one angle, resonance manifolds -- 11.7 Averaging over more than one angle, an introduction -- 11.8 Periodic solutions -- 11.9 Exercises -- 12 Relaxation oscillations -- 12.1 Introduction -- 12.2 The van der Pol-equation -- 12.3 The Volterra-Lotka equations -- 13 Bifurcation theory -- 13.1 Introduction -- 13.2 Normalisation -- 13.3 Averaging and normalisation -- 13.4 Centre manifolds -- 13.5 Bifurcation of equilibrium solutions and Hopf bifurcation -- 13.6 Exercises -- 14 Chaos -- 14.1 The Lorenz-equations -- 14.2 A mapping associated with the Lorenz-equations -- 14.3 A mapping of R into R as a dynamical system -- 14.4 Results for the quadratic mapping -- 15 Hamiltonian systems -- 15.1 Summary of results obtained earlier -- 15.2 A nonlinear example with two degrees of freedom -- 15.3 The phenomenon of recurrence -- 15.4 Periodic solutions -- 15.5 Invariant tori and chaos -- 15.6 The KAM theorem -- 15.7 Exercises -- Appendix 1: The Morse lemma -- Appendix 2: Linear periodic equations with a small parameter -- Appendix 3: Trigonometric formulas and averages -- Answers and hints to the exercises -- References