Convergence to equilibrium of solutions of the backward Euler scheme for asymptotically autonomous second-order gradient-like systems
doi:10.3934/cpaa.2012.11.2393
Maurizio Grasselli - Dipartimento di Matematica, Politecnico di Milano, Via E. Bonardi, 9, I-20133 Milano, Italy (email) Abstract: Following a result of Chill and Jendoubi in the continuous case, we study the asymptotic behavior of sequences $(U^n)_n$ in $R^d$ which satisfy the following backward Euler scheme: $\varepsilon\frac{(U^{n+1}-2U^n+U^{n-1}}{\Delta t^2} +\frac{U^{n+1}-U^n}{\Delta t}+\nabla F(U^{n+1})=G^{n+1}, n\ge 0, $
where $\Delta t>0$ is the time step, $\varepsilon\ge 0$, $(G^{n+1})_n$
is a sequence in $ R^d$ which converges to $0$ in a suitable way,
and $F\in C^{1,1}_{l o c}(R^d, R)$ is a function which satisfies a Łojasiewicz inequality.
We prove that the above scheme is Lyapunov stable and that any bounded sequence $(U^n)_n$
which complies with it converges to a critical point of $F$ as $n$ tends to $\infty$.
We also obtain convergence rates. We assume that $F$ is semiconvex for some constant $c_F\ge 0$
and that $1/\Delta t
Keywords: Łojasiewicz inequality, gradient-like systems, backward Euler scheme, proximal method
Received: October 2010;
Revised:
December 2010;
Published: April 2012. |
2011 Impact Factor.692
|