Second microlocalization and stabilization of damped wave equations on tori
Presenter
October 29, 2015
Keywords:
- compact Riemannian manifold
- regularity of initial data
- damping coefficients
- dampened wave equation
- essentially bounded coefficients
MSC:
- 34H15
- 35R05
- 35L05
- 35A27
- 60J35
- 35R01
- 35R15
Abstract
We consider the question of stabilization for the damped wave equation on tori
(∂^2_t−Δ)u+a(x)∂_t u=0.
When the damping coefficient $a(x)$ is continuous the question is quite well understood and the geometric control condition is necessary and sufficient for uniform (hence exponential) decay to hold. When $a(x)$ is only $L^{\infty}$ there are still gaps in the understanding.
Using second microlocalization we completely solve the question for damping coefficients of the form a(x)=∑_{i=1}^J a_j 1_{x∈R_j}, where $R_j$ are cubes.
This is a joint work with P. Gérard.