Stable Manifold Theorem

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(New page: {{Start Hierarchy|link=Main Page|title=Main Page}} {{Hierarchy Item|link=Bill:Lee|title=Bill:Lee}} {{Hierarchy Item|link=Mathematics|title=Mathematics}} {{End Hierarchy}} Let $E$ be an op...)
 
 
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Let $E$ be an open subset of $\mathbb{R}^n$ containing the origin, let
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Let <math>E</math> be an open subset of <math>\mathbb{R}^{n}</math>, which contains the origin, let <math>\textbf{f}\in C^{1}(E)</math>, and let <math>\phi_{t} </math> be the flow of the nonliear system <math>\dot{\textbf{x}} = \textbf{f}(\textbf{x})</math>. Suppose <math>\textbf{f}(\textbf{0})=\textbf{0}</math> and that <math>D\textbf{f}(\textbf{0})</math> has <math>k</math> eigenvalues with negative real part and <math>n-k</math> eigenvalues with positive real part. Then there exists a <math>k-</math>dimensional differentiable manifold <math>S</math> tangent to the sable subspace <math>E^{s}</math> of the linear system <math>\dot{\textbf{x}} =\textbf{Ax}</math> at <math>\textbf{0}</math>such that for all <math>t\geq 0</math>, <math>\phi_{t}(S) \sub S</math> and for all <math>\textbf{x}_{0} \in S</math>, <math>\lim_{t\to\infty} \phi_{t}(\textbf{x}_{0}) = \textbf{0}</math>; and there exists an <math>n-k</math> dimensional differentiable manifold <math>U</math> tangent to the unstable subspace <math>E^{u}</math>of the linear system at <math>\textbf{0}</math> such that for all <math>t\leq 0</math>, <math>\phi_{t}(U)\sub U</math> and for all <math>\textbf{x}_{0}\in U</math>, <math>\lim_{t\to -\infty} \phi_{t}(\textbf{x}_{0})=\textbf{0}</math>
$f\in C^1(E)$, and let $\phi_t$ be the flow of the nonlinear system $x'=f(x)$.
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Suppose that $f(x_0)=0$ and that $Df(x_0)$ has $k$ eigenvalues with negative real part and $n-k$ eigenvalues with positive real part. Then there exists a $k$-dimensional differentiable manifold $S$ tangent to the stable subspace $E^S$ of the linear system $x'=Df(x)x$ at $x_0$ such that for all $t\geq 0$, $\phi_t(S)\subset S$ and for all $y\in S$,
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\[
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==References==
\lim_{t\to\infty}\phi_t(y)=x_0
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[http://books.google.com/books?id=A7fvvz9Puf8C&dq=differential+equations+and+dynamical+systems+perko&pg=PP1&ots=_DkccInx4B&sig=K27_M_77UOxgOjIJp41B-zz__4I&hl=en&prev=http://www.google.com/search%3Fhl%3Den%26client%3Dsafari%26rls%3Den%26q%3Ddifferential%2Bequations%2Band%2Bdynamical%2Bsystems%2BPerko%26btnG%3DSearch&sa=X&oi=print&ct=title&cad=one-book-with-thumbnail Differential Equations and Dynamical Systems] : Lawrence Perko, page 109, theorem 2, third edition
\]
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and there exists an $n-k$ dimensional differentiable manifold $U$ tangent to the unstable subspace $E^U$ of $x'=Df(x)x$ at $x_0$ such that for all
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$t\leq 0$, $\phi_t(U)\subset U$ and for all $y\in U$,
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\[
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\lim_{t\to -\infty}\phi_t(y)=x_0.
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\]
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Latest revision as of 03:56, 28 May 2008

Main Page > Bill:Lee > Mathematics

Let E be an open subset of \mathbb{R}^{n}, which contains the origin, let \textbf{f}\in C^{1}(E), and let φt be the flow of the nonliear system \dot{\textbf{x}} = \textbf{f}(\textbf{x}). Suppose \textbf{f}(\textbf{0})=\textbf{0} and that D\textbf{f}(\textbf{0}) has k eigenvalues with negative real part and nk eigenvalues with positive real part. Then there exists a kdimensional differentiable manifold S tangent to the sable subspace Es of the linear system \dot{\textbf{x}} =\textbf{Ax} at \textbf{0}such that for all t\geq 0, \phi_{t}(S) \sub S and for all \textbf{x}_{0} \in S, \lim_{t\to\infty} \phi_{t}(\textbf{x}_{0}) = \textbf{0}; and there exists an nk dimensional differentiable manifold U tangent to the unstable subspace Euof the linear system at \textbf{0} such that for all t\leq 0, \phi_{t}(U)\sub U and for all \textbf{x}_{0}\in U, \lim_{t\to -\infty} \phi_{t}(\textbf{x}_{0})=\textbf{0}


References

Differential Equations and Dynamical Systems : Lawrence Perko, page 109, theorem 2, third edition

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