NONLINEAR SCIENCE WORLD SCIENTIFIC SERIES ON Series A Vol. 66 Series Editor: Leon O. Chua DIFFERENTIAL GEOMETRY APPLIED TO DYNAMICAL SYSTEMS Jean-Marc Ginoux Université du Sud, France World Scientific NEW JERSEY • LONDON • SINGAPORE • BEIJING • SHANGHAI • HONG KONG • TA I P E I • CHENNAI Contents I Dynamical Systems 18 1 Introduction 1.1 Galileo’s pendulum . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 D’Alembert transformation . . . . . . . . . . . . . . . . . . . . . 1.3 From differential equations to dynamical systems . . . . . . . . . 19 19 21 22 2 Dynamical Systems 2.1 State space – phase space . . . . . . . . . . . . 2.2 Definition . . . . . . . . . . . . . . . . . . . . . 2.3 Existence and uniqueness . . . . . . . . . . . . . 2.4 Flow, fixed points and null-clines . . . . . . . . . 2.5 Stability theorems . . . . . . . . . . . . . . . . . 2.5.1 Linearized system . . . . . . . . . . . . 2.5.2 Hartman-Grobman linearization theorem 2.5.3 Liapounoff stability theorem . . . . . . . 2.6 Phase portraits of dynamical systems . . . . . . . 2.6.1 Two-dimensional systems . . . . . . . . 2.6.2 Three-dimensional systems . . . . . . . . 2.7 Various types of dynamical systems . . . . . . . 2.7.1 Linear and nonlinear dynamical systems . 2.7.2 Homogeneous dynamical systems . . . . 2.7.3 Polynomial dynamical systems . . . . . . 2.7.4 Singularly perturbed systems . . . . . . . 2.7.5 Slow-Fast dynamical systems . . . . . . 2.8 Two-dimensional dynamical systems . . . . . . . 2.8.1 Poincaré index . . . . . . . . . . . . . . 2.8.2 Poincaré contact theory . . . . . . . . . . 2.8.3 Poincaré limit cycle . . . . . . . . . . . . 2.8.4 Poincaré-Bendixson Theorem . . . . . . 2.9 High-dimensional dynamical systems . . . . . . 2.9.1 Attractors . . . . . . . . . . . . . . . . . 23 23 24 24 25 29 29 29 29 30 30 34 37 37 38 38 39 39 40 40 42 42 44 46 46 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CONTENTS 2 2.9.2 Strange attractors . . . . . . . . 2.9.3 First integrals and Lie derivative 2.10 Hamiltonian and integrable systems . . 2.10.1 Hamiltonian dynamical systems 2.10.2 Integrable system . . . . . . . . 2.10.3 K.A.M. Theorem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 49 49 49 50 52 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 54 54 55 55 55 56 . . . . . . . . . . . 59 59 59 60 61 64 65 70 72 73 75 77 . . . . . . . . 78 78 81 81 82 83 89 89 90 6 Integrability 6.1 Integrability conditions, integrating factor and multiplier . . . . . 6.1.1 Two-dimensional dynamical systems . . . . . . . . . . . 92 92 93 3 Invariant Sets 3.1 Manifold . . . . . . . . 3.1.1 Definition . . . . 3.1.2 Existence . . . . 3.2 Invariant sets . . . . . . 3.2.1 Global invariance 3.2.2 Local invariance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Local Bifurcations 4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . 4.2 Center Manifold Theorem . . . . . . . . . . . . . . 4.2.1 Center manifold theorem for flows . . . . . . 4.2.2 Center manifold approximation . . . . . . . 4.2.3 Center manifold depending upon a parameter 4.3 Normal Form Theorem . . . . . . . . . . . . . . . . 4.4 Local Bifurcations of Codimension 1 . . . . . . . . . 4.4.1 Saddle-node bifurcation . . . . . . . . . . . 4.4.2 Transcritical bifurcation . . . . . . . . . . . 4.4.3 Pitchfork bifurcation . . . . . . . . . . . . . 4.4.4 Hopf bifurcation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Slow-Fast Dynamical Systems 5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2 Geometric Singular Perturbation Theory . . . . . . . . . . . 5.2.1 Assumptions . . . . . . . . . . . . . . . . . . . . . 5.2.2 Invariance . . . . . . . . . . . . . . . . . . . . . . . 5.2.3 Slow invariant manifold . . . . . . . . . . . . . . . 5.3 Slow-fast dynamical systems – Singularly perturbed systems 5.3.1 Singularly perturbed systems . . . . . . . . . . . . . 5.3.2 Slow-fast autonomous dynamical systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CONTENTS 6.2 6.3 3 6.1.2 Three-dimensional dynamical systems . . . . . . . . . . . 96 First integrals – Jacobi’s last multiplier theorem . . . . . . . . . . 101 6.2.1 Jacobi’s last multiplier theorem . . . . . . . . . . . . . . 102 Darboux theory of integrability . . . . . . . . . . . . . . . . . . . 103 6.3.1 Algebraic particular integral – General integral . . . . . . 103 6.3.2 General integral . . . . . . . . . . . . . . . . . . . . . . . 105 6.3.3 Multiplier . . . . . . . . . . . . . . . . . . . . . . . . . . 107 6.3.4 Algebraic particular integral and fixed points . . . . . . . 108 6.3.5 Homogeneous polynomial dynamical system of degree m 109 6.3.6 Homogeneous polynomial dynamical system of degree two 115 6.3.7 Planar polynomial dynamical systems . . . . . . . . . . . 121 II Differential Geometry 126 7 Differential Geometry 7.1 Concept of curves – Kinematics vector functions . . . . . 7.1.1 Trajectory curve . . . . . . . . . . . . . . . . . . 7.1.2 Instantaneous velocity vector . . . . . . . . . . . . 7.1.3 Instantaneous acceleration vector . . . . . . . . . 7.2 Gram-Schmidt process – Generalized Frénet moving frame 7.2.1 Gram-Schmidt process. . . . . . . . . . . . . . . 7.2.2 Generalized Frénet moving frame. . . . . . . . . . 7.3 Curvatures of trajectory curves – Osculating planes . . . . 7.4 Curvatures and osculating plane of space curves . . . . . . 7.4.1 Frénet trihedron – Serret-Frénet formulae . . . . . 7.4.2 Osculating plane . . . . . . . . . . . . . . . . . . 7.4.3 Curvatures of space curves . . . . . . . . . . . . . 7.5 Flow curvature method . . . . . . . . . . . . . . . . . . . 7.5.1 Flow curvature manifold . . . . . . . . . . . . . . 7.5.2 Flow curvature method . . . . . . . . . . . . . . . 127 128 128 128 129 129 130 130 131 133 133 134 135 136 136 137 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Dynamical Systems 138 8.1 Phase portraits of dynamical systems . . . . . . . . . . . . . . . . 138 8.1.1 Fixed points . . . . . . . . . . . . . . . . . . . . . . . . . 138 8.1.2 Stability theorems . . . . . . . . . . . . . . . . . . . . . 140 9 Invariant Sets 148 9.1 Invariant manifolds . . . . . . . . . . . . . . . . . . . . . . . . . 148 9.1.1 Global invariance . . . . . . . . . . . . . . . . . . . . . . 149 9.1.2 Local invariance . . . . . . . . . . . . . . . . . . . . . . 149 CONTENTS 9.2 9.3 4 Linear invariant manifolds . . . . . . . . . . . . . . . . . . . . . 151 Nonlinear invariant manifolds . . . . . . . . . . . . . . . . . . . 157 10 Local Bifurcations 10.1 Center Manifold . . . . . . . . . . . . . . . . . . . . 10.1.1 Center manifold approximation . . . . . . . 10.1.2 Center manifold depending upon a parameter 10.2 Normal Form Theorem . . . . . . . . . . . . . . . . 10.3 Local bifurcations of codimension 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Slow-Fast Dynamical Systems 11.1 Slow manifold of n-dimensional slow-fast dynamical systems . 11.2 Invariance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.3 Flow Curvature Method – Singular Perturbation Method . . . 11.3.1 Darboux invariance – Fenichel’s invariance . . . . . . 11.3.2 Slow invariant manifold . . . . . . . . . . . . . . . . 11.4 Non-singularly perturbed systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 160 160 167 174 179 . . . . . . 180 181 184 185 187 188 197 12 Integrability 199 12.1 First integral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199 12.1.1 Global first integral . . . . . . . . . . . . . . . . . . . . . 199 12.1.2 Local first integral . . . . . . . . . . . . . . . . . . . . . 200 12.2 Linear invariant manifolds as first integral . . . . . . . . . . . . . 201 12.3 Darboux theory of integrability . . . . . . . . . . . . . . . . . . . 205 12.3.1 General integral – Multiplier . . . . . . . . . . . . . . . . 205 12.3.2 Homogeneous polynomial dynamical system of degree two 207 12.3.3 Planar polynomial dynamical systems . . . . . . . . . . . 208 13 Inverse Problem 13.1 Flow curvature manifold of polynomial dynamical systems 13.1.1 Two-dimensional polynomial dynamical systems . 13.1.2 Three-dimensional polynomial dynamical systems 13.2 Inverse problem for polynomial dynamical systems . . . . 13.2.1 Two-dimensional polynomial dynamical systems . 13.2.2 Three-dimensional polynomial dynamical systems III Applications . . . . . . . . . . . . . . . . . . . . . . . . 210 210 210 212 214 214 215 217 14 Dynamical Systems 218 14.1 FitzHugh-Nagumo model . . . . . . . . . . . . . . . . . . . . . . 218 14.2 Pikovskii-Rabinovich-Trakhtengerts model . . . . . . . . . . . . 219 CONTENTS 5 15 Invariant sets - Integrability 15.1 Pikovskii-Rabinovich-Trakhtengerts model 15.2 Rikitake model . . . . . . . . . . . . . . . 15.3 Chua’s model . . . . . . . . . . . . . . . . 15.4 Lorenz model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 220 223 224 225 16 Local bifurcations 227 16.1 Chua’s model . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 16.2 Lorenz model . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 17 Slow-Fast Dynamical Systems 17.1 Piecewise Linear Models 2D & 3D . . . . . . . . . 17.1.1 Van der Pol piecewise linear model . . . . 17.1.2 Chua’s piecewise linear model . . . . . . . 17.2 Singularly Perturbed Systems 2D & 3D . . . . . . 17.2.1 FitzHugh-Nagumo model . . . . . . . . . 17.2.2 Chua’s model . . . . . . . . . . . . . . . . 17.3 Slow Fast Dynamical Systems 2D & 3D . . . . . . 17.3.1 Brusselator model . . . . . . . . . . . . . 17.3.2 Pikovskii-Rabinovich-Trakhtengerts model 17.3.3 Rikitake model . . . . . . . . . . . . . . . 17.4 Piecewise Linear Models 4D & 5D . . . . . . . . . 17.4.1 Chua’s fourth-order piecewise linear model 17.4.2 Chua’s fifth-order piecewise linear model . 17.5 Singularly Perturbed Systems 4D & 5D . . . . . . 17.5.1 Chua’s fourth-order cubic model . . . . . . 17.5.2 Chua’s fifth-order cubic model . . . . . . . 17.6 Slow Fast Dynamical Systems 4D & 5D . . . . . . 17.6.1 Homopolar dynamo model . . . . . . . . . 17.6.2 Mofatt model . . . . . . . . . . . . . . . . 17.6.3 Magnetoconvection model . . . . . . . . . 17.7 Slow manifold gallery . . . . . . . . . . . . . . . . 17.8 Forced Van der Pol model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Discussion 18 Appendix 18.1 Lie derivative . . 18.2 Hessian . . . . . 18.3 Jordan form . . . 18.4 Connected region 231 231 231 233 235 235 236 237 237 238 239 240 240 242 244 244 245 246 246 248 249 251 252 254 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 257 257 258 259 CONTENTS 18.5 Fractal dimension . . . . . . . . . . . . . . . . . . . . . . . . . . 18.5.1 Kolmogorov or capacity dimension . . . . . . . . . . . . 18.5.2 Liapounoff exponents – Wolf, Swinney, Vastano algorithm 18.5.3 Liapounoff dimension and Kaplan-Yorke conjecture . . . 18.5.4 Liapounoff dimension and Chlouverakis-Sprott conjecture 18.6 Identities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18.6.1 Concept of curves . . . . . . . . . . . . . . . . . . . . . 18.6.2 Gram-Schmidt process and Frénet moving frame . . . . . 18.6.3 Frénet trihedron and curvatures of space curves . . . . . . 18.6.4 First identity . . . . . . . . . . . . . . . . . . . . . . . . 18.6.5 Second identity . . . . . . . . . . . . . . . . . . . . . . . 18.6.6 Third identity . . . . . . . . . . . . . . . . . . . . . . . . 18.7 Homeomorphism and diffeomorphism . . . . . . . . . . . . . . . 18.7.1 Homeomorphism . . . . . . . . . . . . . . . . . . . . . . 18.7.2 Diffeomorphism . . . . . . . . . . . . . . . . . . . . . . 18.8 Differential equations . . . . . . . . . . . . . . . . . . . . . . . 18.8.1 Two-dimensional dynamical systems . . . . . . . . . . . 18.8.2 Three-dimensional dynamical systems . . . . . . . . . . . 18.9 Generalized Tangent Linear System Approximation . . . . . . . . 18.9.1 Assumptions . . . . . . . . . . . . . . . . . . . . . . . . 18.9.2 Corollaries . . . . . . . . . . . . . . . . . . . . . . . . . 6 259 260 261 262 263 263 264 264 267 268 269 270 270 270 270 271 271 271 272 272 273 Mathematica Files 277 Bibliography 282 Index 297 List of Figures 1 Synopsis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 1.1 Galileo’s pendulum . . . . . . . . . . . . . . . . . . . . . . . . . 20 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 Free fall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Volterra-Lotka predator-prey model . . . . . . . . . . . . . . . . Phase plane stability diagram . . . . . . . . . . . . . . . . . . . . Inverted pendulum . . . . . . . . . . . . . . . . . . . . . . . . . stability diagram . . . . . . . . . . . . . . . . . . . . . . . . . . Saddle-focus . . . . . . . . . . . . . . . . . . . . . . . . . . . . Poincaré limit cycle . . . . . . . . . . . . . . . . . . . . . . . . . Duffing oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . Lorenz butterfly . . . . . . . . . . . . . . . . . . . . . . . . . . . Spherical pendulum . . . . . . . . . . . . . . . . . . . . . . . . . Hénon-Heiles Hamiltonian . . . . . . . . . . . . . . . . . . . . . Transversal Poincaré section (p2 , q2 ) of Hénon-Heiles Hamiltonian 26 27 32 33 36 37 43 45 48 51 53 53 3.1 Stable W S and unstable W U manifolds . . . . . . . . . . . . . . 58 4.1 Part of the center manifold in green . . . . . . . . . . . . . . . . 61 6.1 General integral . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 7.1 Osculating plane . . . . . . . . . . . . . . . . . . . . . . . . . . 134 8.1 Duffing oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . 144 9.1 Local invariance . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 10.1 Center manifold . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 11.1 Van der Pol slow manifold . . . . . . . . . . . . . . . . . . . . . 192 11.2 Chua’s slow invariant manifold in (xz)-plane . . . . . . . . . . . 196 11.3 Lorenz slow manifold . . . . . . . . . . . . . . . . . . . . . . . . 198 LIST OF FIGURES 8 12.1 Local first integral of Van der Pol model . . . . . . . . . . . . . . 201 12.2 Volterra-Lotka’s first integral . . . . . . . . . . . . . . . . . . . . 204 12.3 First integral of quadratic system . . . . . . . . . . . . . . . . . . 206 17.1 Van der Pol piecewise linear model slow invariant manifold . . 17.2 Chua’s piecewise linear model slow invariant manifold . . . . 17.3 FitzHugh-Nagumo model slow invariant manifold . . . . . . . 17.4 Chua’s cubic model slow invariant manifold . . . . . . . . . . 17.5 Brusselator’s model slow invariant manifold . . . . . . . . . . 17.6 (PRT) model slow invariant manifold . . . . . . . . . . . . . 17.7 Rikitake model slow invariant manifold . . . . . . . . . . . . 17.8 Chua’s model invariant hyperplanes in (x1 , x2 , x3 ) phase space 17.9 Chua’s model invariant hyperplanes in (x1 , x2 , x3 ) phase space 17.10 Chua’s model slow invariant manifold . . . . . . . . . . . . . 17.11 Chua’s slow invariant manifold . . . . . . . . . . . . . . . . 17.12 Dynamo model slow invariant manifold . . . . . . . . . . . . 17.13 Mofatt model slow invariant manifold . . . . . . . . . . . . . 17.14 Magnetoconvection slow invariant manifold . . . . . . . . . . 17.15 Chemical kinetics model - Neuronal bursting model . . . . . 17.16 Forced Van der Pol model slow invariant manifold . . . . . . 17.17 Chua’s cubic model attractor structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 234 235 236 237 238 239 242 243 245 246 247 248 250 251 253 256 List of Tables 15.1 Invariant manifolds of the (PRT) model . . . . . . . . . . . . . . 222 15.2 Invariant manifolds of the Rikitake model . . . . . . . . . . . . . 223 15.3 Invariant manifolds of the Lorenz model . . . . . . . . . . . . . . 226 Index attractor, 46, 47, 251, 255, 260, 262 187, 199, 204, 205, 207–209, 221, attractor structure, 256 255 autonomous, 17, 23, 24, 28, 59, 249, 252, Darboux invariance theorem, 15, 16, 103, 255 104, 148, 149, 181, 183, 187, 232, 234–239, 241, 243, 244, 246, 247, Bendixson, 44–46 249, 250, 252, 254, 255 bifurcation, 59, 60, 64, 68, 72, 74, 76, 77, diffeomorphism, 29, 270 127, 137, 160, 174, 179, 229, 230, differential equation, 13, 19–24, 27, 41, 42, 278–280 44, 46, 59, 62, 64, 70, 92, 93, 95– Brusselator, 16, 219, 237, 281 101, 127, 138, 160, 167, 181, 219, 223, 224, 240, 242, 244, 245, 271, Cauchy, 13, 24, 25, 40, 46, 59, 89, 93, 96, 272 99, 127, 128, 138, 160, 167, 181, differential geometry, 13, 14, 17, 127, 131, 210, 212 154, 181, 254, 263, 278 centre manifold, 15, 16, 54, 58, 60–65, 68, 70–72, 82, 127, 137, 160, 161, 163, dissipative, 46–48, 101, 260, 262 164, 166–171, 174, 179, 227, 229, divergence, 47, 93, 97 Duffing, 45, 144, 169, 170, 277–279 230, 254, 255, 278, 279 dynamical system, 13–16, 18, 22–30, 33, chaotic attractor, 238 34, 37–47, 49, 50, 54–66, 68–70, Chua, 14, 16, 38, 80, 88, 89, 195, 219, 224, 72–74, 76–78, 89–92, 95–97, 99– 225, 227, 233, 234, 236, 240–246, 101, 103–115, 118, 119, 127, 128, 256, 278–281 131–138, 140–142, 144–150, 155– Chua’s invariant hyperplanes, 242, 243 157, 159–161, 163, 164, 166–169, Chua’s slow invariant manifold, 196, 236 171, 174, 175, 178, 180–183, 185, codimension, 64, 70, 137, 160, 179, 230 188, 192, 193, 197, 199–202, 205, complex dynamics, 80 207, 208, 210, 212–216, 228, 229, conservative, 47, 50, 101, 262 254, 255, 257, 264, 266, 272–275, curvature, 13, 14, 127, 129, 131–136, 154– 277, 278, 280 156, 181, 192, 197, 202, 254, 255, 263, 264, 266–268 Fenichel, 15, 78, 79, 81, 82, 85, 88, 91, 180, curvature of the flow, 13 185, 187, 254 curve, 13, 27, 40–42, 44, 72, 93, 99, 101, first integral, 14–16, 49–51, 100–102, 104– 102, 128, 131–136, 139, 154, 263, 106, 108, 110, 111, 114–119, 122– 264, 266, 267, 271 125, 148, 149, 156, 199–209, 221, 224, 225, 254, 255, 278, 279 Darboux, 14, 16, 94, 99, 101, 103–118, 121, 123, 124, 148, 149, 159, 183, 184, FitzHugh-Nagumo, 16, 218, 235, 280, 281 INDEX 300 non-autonomous, 231, 252 148, 180, 181, 186, 188, 189, 193, non-singularly perturbed systems, 16, 90, 194, 197, 200, 231, 235, 236, 238, 91, 197, 255, 279 239, 244, 247–249, 254, 255, 281 nonlinear invariant manifold, 157, 221, 254 slow invariant manifold, 14–17, 78, 82, 83, normal forms, 15, 65, 66, 68–70, 127, 137, 85, 88, 90, 91, 137, 180, 182, 185– 160, 174, 175, 178, 179, 220, 254, 189, 191, 193, 194, 196, 220, 232, 258 233, 236–240, 243–251, 253–255 null-clines, 25, 26, 28 slow-fast dynamical systems, 14, 39, 78, 89, 90, 180, 181, 184, 185, 192, 231, orbit, 29, 45, 51, 55, 78, 180, 261 237, 255, 278–280 osculating plane, 14, 131–136, 140–144, 146, spherical pendulum, 50, 51, 200, 277 202, 203, 234 stability, 29, 30, 32, 36, 59, 73–75, 127, 137, 138, 140, 142, 144, 147, 148, pendulum, 19, 20, 154 180, 218 phase, 23, 24, 26, 27, 30, 32, 33, 44, 45, strange attractor, 14, 47, 50, 260–263 47, 49, 59, 90, 101, 138, 232, 234, 242, 243, 245–248, 250, 253, 256, tangent linear system approximation, 17, 181– 260 183, 272, 274–276 piecewise linear model, 16, 80, 231–234, torsion, 131, 134–136, 154, 181, 197, 266– 240–243, 280, 281 268 Pikovskii, 16, 158, 219, 220, 238, 280, 281 trajectory curve, 13, 14, 24–26, 42, 44, 46, pitchfork bifurcation, 14, 64, 72, 75, 76, 47, 49–53, 101, 127–132, 136, 137, 137, 160, 174, 179, 229, 230 155, 156, 181, 201, 202, 254–256, Poincaré, 15, 43, 44, 46, 92, 128, 144 260, 261, 263, 264, 266–268 Poincaré index, 14 transcritical, 137, 160, 170, 179 Poincaré section, 53, 260 transcritical bifurcation, 72–74 quadratic system, 206 relaxation oscillations, 27, 39, 231 relaxation oscillator, 79 Rikitake, 16, 223, 239, 246, 255, 280, 281 saddle, 31, 33, 35, 37, 40, 45, 73, 137, 142, 144, 145, 160, 179 saddle points, 52 saddle-focus, 145 saddle-node, 145 saddle-node bifurcation, 72, 73 singular approximation, 39, 85, 88, 90, 190, 192, 195, 200, 201, 235–237 Singular Perturbation Method, 81, 185, 192, 196, 236, 278 singularly perturbed systems, 14–16, 28, 39, 58, 78–80, 82–84, 87, 89–91, 137, Van der Pol, 14, 16, 27, 39, 41, 43, 44, 190, 192, 200, 201, 211, 215, 218, 231, 232, 235, 252, 253, 278–280 Volterra, 27, 28, 37, 118, 153, 156, 204, 279 INDEX fixed point, 15, 16, 25, 26, 28–31, 33–35, 37, 40–46, 55–57, 60, 61, 70, 72– 77, 108, 114, 127, 128, 132, 134, 137–147, 185, 214, 216, 218, 219, 234, 241, 243, 256 fixed point stability, 15, 254 flow curvature manifold, 13, 15, 16, 127, 136–144, 146, 148, 151–154, 156, 157, 159–161, 163, 164, 166–168, 170, 171, 174, 175, 179, 182, 184, 186, 188, 191–193, 196, 197, 201, 202, 204, 206, 207, 209–216, 218– 221, 224, 225, 227, 232–241, 243, 244, 246–250, 252, 254–256 flow curvature method, 13, 15, 17, 90, 109, 127, 136, 137, 159, 185, 186, 190, 192, 195–197, 200, 252, 254–256, 276, 279 Forced Van der Pol, 17, 252, 255, 281 Galois, 147, 181 Geometric Singular Perturbation Theory, 14, 15, 58, 78, 79, 81, 82, 90, 91, 180, 185, 186, 188, 190–193, 195–197, 201, 254, 255, 278 Grobman, 29, 58 Groebner, 215, 216 Hénon-Heiles Hamiltonian, 52, 53, 277 Hamiltonian, 14, 49, 50, 52, 53, 199, 262 harmonic oscillator, 49 Hartman, 29, 58 homeomorphism, 29, 270 homopolar dynamo, 16, 246, 247 Hopf, 77, 137, 160 Hopf bifurcation, 76, 77 hyperbolic, 29, 40, 56, 57, 78, 81, 180 hyperbolic points, 52 299 127, 137, 148–152, 154–159, 180, 184, 199, 201, 224–226 invariant tori, 52 inverse problem, 16, 137, 210, 214, 255, 280 inverted pendulum, 33, 37 Jacobian, 29, 30, 33, 34, 37–39, 41, 54–57, 60, 61, 70, 71, 73–75, 77, 90, 91, 95, 129, 140–142, 145, 146, 161, 180–186, 234, 273–276 Jordan fom, 258, 259 Jordan form, 31, 35, 41, 258 K.A.M. theorem, 14, 52 K.A.M. tori, 52, 53 Kapteyn-Bautin, 125, 209, 278 LaSalle, 54 Liapounoff, 14, 29, 30 Liapounoff dimension, 260, 262, 263 Liapounoff exponents, 261–263 Lie derivative, 14, 15, 42, 49, 94, 119, 140– 142, 149, 150, 153, 154, 157, 158, 184, 187, 192, 197, 200, 201, 221, 226, 232, 234, 237–239, 241, 244, 246, 247, 249, 250, 252, 255, 257 limit cycle, 14, 42–44, 46, 77, 277 linear, 29, 37, 38, 56, 65, 67, 134, 137, 148, 151, 152, 154–156, 159, 175, 180–183, 201, 233, 240–242, 244, 245, 258, 272–276 linear invariant manifold, 15, 153, 156, 202– 205, 207, 208, 220, 254 Liouville, 47, 92, 199, 262 local bifurcations, 254 Lorenz, 16, 48, 90, 91, 147, 197, 198, 212, 216, 225, 226, 229, 230, 249, 255, 263, 278–280 Lorenz butterfly, 48, 277 Lorenz slow manifold, 198 implicit function theorem, 55, 82, 84, 85, 87, 88, 186 integrability, 54, 92–103, 127, 148, 159, 199, 205, 254, 255, 278–280 magnetoconvection, 16, 249, 250, 281 invariant manifold, 54, 56–58, 60, 71, 78, Mofatt, 16, 246, 248, 249, 281 104, 105, 107, 108, 110, 112–115,
© Copyright 2026 Paperzz