{{Short description|Result in dynamical systems theory}} In mathematics, especially in the study of dynamical systems and differential equations, the '''stable manifold theorem''' is an important result about the structure of the set of orbits approaching a given hyperbolic fixed point. It roughly states that the existence of a local diffeomorphism near a fixed point implies the existence of a local stable center manifold containing that fixed point. This manifold has dimension equal to the number of eigenvalues of the Jacobian matrix of the fixed point that are less than 1.<ref>{{cite book |first=Michael |last=Shub |title=Global Stability of Dynamical Systems |publisher=Springer |year=1987 |pages=65–66 |url=https://books.google.com/books?id=d-XgBwAAQBAJ&pg=PA65 }}</ref>
== Stable manifold theorem == Let :<math>f: U \subset \mathbb{R}^n \to \mathbb{R}^n</math> be a smooth map with hyperbolic fixed point at <math>p</math>. We denote by <math>W^{s}(p)</math> the stable set and by <math>W^{u}(p)</math> the unstable set of <math>p</math>.
The theorem<ref>{{cite journal|last = Pesin|first = Ya B|title = Characteristic Lyapunov Exponents and Smooth Ergodic Theory|journal = Russian Mathematical Surveys|year = 1977|volume = 32|issue = 4|pages = 55–114|doi = 10.1070/RM1977v032n04ABEH001639|url = http://www.turpion.org/php/paper.phtml?journal_id=rm&paper_id=1639|access-date = 2007-03-10|bibcode=1977RuMaS..32...55P| s2cid=250877457 |url-access = subscription}}</ref><ref>{{cite journal|last = Ruelle|first = David|title = Ergodic theory of differentiable dynamical systems|journal = Publications Mathématiques de l'IHÉS|year = 1979|volume = 50|pages = 27–58|url = http://www.numdam.org/numdam-bin/item?h=nc&id=PMIHES_1979__50__27_0|access-date = 2007-03-10|doi=10.1007/bf02684768| s2cid=56389695 }}</ref><ref>{{cite book| last = Teschl| given = Gerald|author-link=Gerald Teschl| title = Ordinary Differential Equations and Dynamical Systems| publisher=American Mathematical Society| place = Providence| year = 2012| isbn= 978-0-8218-8328-0| url = https://www.mat.univie.ac.at/~gerald/ftp/book-ode/}}</ref> states that * <math>W^{s}(p)</math> is a smooth manifold and its tangent space has the same dimension as the stable space of the linearization of <math>f</math> at <math>p</math>. * <math>W^{u}(p)</math> is a smooth manifold and its tangent space has the same dimension as the unstable space of the linearization of <math>f</math> at <math>p</math>.
Accordingly <math>W^{s}(p)</math> is a '''stable manifold''' and <math>W^{u}(p)</math> is an '''unstable manifold'''.
== See also == * Center manifold theorem * Lyapunov exponent
== Notes== <references responsive="0"/>
== References == *{{cite book |first=Lawrence |last=Perko |title=Differential Equations and Dynamical Systems |location=New York |publisher=Springer |edition=Third |year=2001 |isbn=0-387-95116-4 |pages=105–117 }} *{{cite book |first=S. S. |last=Sritharan |title=Invariant Manifold Theory for Hydrodynamic Transition |publisher=John Wiley & Sons |year=1990 |isbn=0-582-06781-2 }}
== External links == *{{PlanetMath|title=StableManifoldTheorem|urlname=StableManifoldTheorem}}
Category:Dynamical systems Category:Theorems in dynamical systems