A note on the necessity of filtering mechanism for polynomial observability of time-discrete wave equation
Journal Title: Карпатські математичні публікації - Year 2017, Vol 9, Issue 1
Abstract
The problem of uniform polynomial observability was recently analyzed. It is shown that, when the continuous model is uniformly polynomially observable, it is sufficient to filter initial data to derive uniform polynomial observability inequalities for suitable time-discretization schemes. In this note, we prove that a filtering mechanism of high frequency modes is necessary to obtain uniform polynomial observability. More precisely, we give a counterexample which proves that this latter fails without filtering the initial data for time semi-discrete approximations of the wave equation.
Authors and Affiliations
Z. Hajjej
On an approach to the construction of the Friedrichs and Neumann-Krein extensions of nonnegative linear relations
Let L0 be a closed linear nonnegative (probably, positively defined) relation ("multivalued operator") in a complex Hilbert space H. In terms of the so called boundary value spaces (boundary triples) and corresponding We...
On the growth of a klasss of Dirichlet series absolutely convergent in half-plane
In terms of generalized orders it is investigated a relation between the growth of a Dirichlet series $F(s)=\sum\limits_{n=1}^{\infty}a_n\exp\{s\lambda_n\}$ with the abscissa of asolute convergence $A\in (-\infty,+\infty...
Generalized types of the growth of Dirichlet series
Let A∈(−∞,+∞] and Φ be a continuously on [σ0,A) function such that Φ(σ)→+∞ as σ→A−0. We establish a necessary and sufficient condition on a nonnegative sequence λ=(λn), increasing to +∞, under which the equality ¯¯¯¯¯¯¯¯...
On the crossings number of a hyperplane by a stable random process
The numbers of crossings of a hyperplane by discrete approximations for trajectories of an α-stable random process (with 1<α<2) and some processes related to it are investigated. We consider an α-stable process is killed...
Continuously differentiable solutions of one boundary value problem for a systems of linear difference differential equations of neutral type
Conditions of the existence of continuously differentiable bounded for t∈R+ solutions of one boundary value problem for a systems of linear and nonlinear difference differential equations of neutral type have been obtain...