420 likes | 534 Views
Optimality on Polynomial decay of semigroups in Elasticity By Jaime E. Muñoz Rivera LNCC IM-UFRJ. Our problem :. Given a semigroup of contractions T(t) defined over Hilbert space H, find the best number p such that. know result about Polynomial stability.
E N D
Optimality on Polynomial decay of semigroups in Elasticity By Jaime E. Muñoz Rivera LNCC IM-UFRJ
Our problem: Given a semigroup of contractions T(t) defined over Hilbert space H, find the best number p such that
knowresultabout Polynomialstability
Liu and Rao proved a sufficient condition to get the polynomial decay of a semigroup
A sufficient and a necessary condition to polynomial decay was given by J. Pruss 2006
Pruss method give a necessary and a sufficient condition to prove polynomial estability The problem is that it is not a simple task to estimate fractional powers of the operator of I.G.S. It is more easy to deal with the sufficient condition given by Liu and Rao. Our purporse is to show that the sufficient condition of Liu and Rao is also a necessary condition
The nexus between Liu-Rao and Pruss Characterization is given by a result due to
This is a join work with Luci Fatori: Estadual University of Londrina Paraná – Brasil e-mail: lucifatori@uel.br Our interest is to prove that the sufficient condition of Liu and Rao is also a necessary condition.
Our main result is the following necessary condition This result will be important to show when a rate of decay is optimal. The proof is based on Pruss necessary condition and Latushkin –Shvidkoy result.
The Infenitesimal generator of the semigroup is We denote the associated semigroup as
That system was studied by Chen and Triggiani. They proved that the semigroup is analytic if The authors solved the conjetures of G. Chen and D. L. Russel on structural damping for elastic systems.
Z. Liu and K. Liu, proved that the semigroup is analytic when and Differentiable when
Our Contribution
Our contribution is about polynomial stability for Our stability result to damped wave equation is
Our contribution to Bresse system