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Eurasian Mathematical Journal, 2010, Volume 1, Number 4, Pages 116–123
(Mi emj38)
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Justification of the dynamical systems method for global homeomorphism
A. G. Ramm Department of Mathematics, Kansas State University, Manhattan, KS, USA
Abstract:
The dynamical systems method (DSM) is justified for solving operator equations $F(u)=f$, where $F$ is a nonlinear operator in a Hilbert space $H$. It is assumed that $F$ is a global homeomorphism of $H$ onto $H$, that $F\in C^1_{loc}$, that is, it has the Fréchet derivative $F'(u)$ continuous with respect to $u$, that the operator $[F'(u)]^{-1}$ exists for all $u\in H$ and is bounded, $||[F'(u)]^{-1}||\leq m(u)$, where $m(u)>0$ depends on $u$, and is not necessarily uniformly bounded with respect to $u$. It is proved under these assumptions that the continuous analogue of the Newton's method
\begin{equation}
\dot u=-[F'(u)]^{-1}(F(u)-f),\qquad u(0)=u_0,
\tag{1}
\end{equation}
converges strongly to the solution of the equation $F(u)=f$ for any $f\in H$ and any $u_0\in H$. The global (and even local) existence of the solution to the Cauchy problem $(1)$ was not established earlier without assuming that $F'(u)$ is Lipschitz-continuous. The case when $F$ is not a global homeomorphism but a monotone operator in $H$ is also considered.
Keywords and phrases:
the dynamical systems method (DSM), surjectivity, global homeomorphisms, monotone operators.
Received: 19.07.2010
Citation:
A. G. Ramm, “Justification of the dynamical systems method for global homeomorphism”, Eurasian Math. J., 1:4 (2010), 116–123
Linking options:
https://www.mathnet.ru/eng/emj38 https://www.mathnet.ru/eng/emj/v1/i4/p116
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Abstract page: | 189 | Full-text PDF : | 70 | References: | 31 |
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