93 research outputs found
Local energy decay in even dimensions for the wave equation with a time-periodic non-trapping metric and applications to Strichartz estimates
We obtain local energy decay as well as global Strichartz estimates for the
solutions of the wave equation $\partial_t^2 u-div_x(a(t,x)\nabla_xu)=0,\
t\in{\R},\ x\in{\R}^n,a(t,x)1xR_\chi(\theta)=\chi(\mathcal U(T, 0)-e^{-i\theta})^{-1}\chi\mathcal U(T, 0)Ta(t,x)\{\theta\in\mathbb{C}\ :\
\textrm{Im}(\theta) \geq 0\}n \geq 3\{
\theta\in\mathbb C\ :\ \textrm{Im}(\theta)\geq0,\ \theta\neq 2k\pi-i\mu,\
k\in\mathbb{Z},\ \mu\geq0\}n \geq4n \geq4R_\chi(\theta)\theta=0$
Local energy decay for the wave equation with a time-periodic non-trapping metric and moving obstacle
Consider the mixed problem with Dirichelet condition associated to the wave
equation \partial_t^2u-\Div_{x}(a(t,x)\nabla_{x}u)=0, where the scalar metric
is -periodic in and uniformly equal to 1 outside a compact set
in , on a -periodic domain. Let be the associated
propagator. Assuming that the perturbations are non-trapping, we prove the
meromorphic continuation of the cut-off resolvent of the Floquet operator
and establish sufficient conditions for local energy decay.Comment: Corrections of some misprint
On the meromorphic continuation of the resolvent for the wave equation with time-periodic perturbation and applications
Consider the wave equation , where
with and is -periodic in time and decays
exponentially in space. Let be the associated propagator and let
be the resolvent of
the Floquet operator defined for \im(\theta)>BT with
sufficiently large. We establish a meromorphic continuation of from
which we deduce the asymptotic expansion of
, where , as with a remainder term whose energy decays
exponentially when is odd and a remainder term whose energy is bounded with
respect to , with , when is even. Then,
assuming that has no poles lying in $\{\theta\in\C\ :\
\im(\theta)\geq0\}\theta\to0\partial_t^2u-\Delta_xu+V(t,x)u=F(t,x)$
Strichartz estimates without loss on manifolds with hyperbolic trapped geodesics
Doi proved that the local smoothing effect for
Schr\"odinger equation on a Riemannian manifold does not hold if the geodesic
flow has one trapped trajectory. We show in contrast that Strichartz estimates
and dispersive estimates still hold without loss for
in various situations where the trapped set is hyperbolic and of
sufficiently small fractal dimension.Comment: 23 pages. Corrections in the proof of prop 3.
Uniform resolvent estimates for Schr\"odinger operator with an inverse-square potential
We study the uniform resolvent estimates for Schr\"odinger operator with a
Hardy-type singular potential.
Let where is the usual Laplacian on
and where and
is a real function such that
the operator is a strictly positive
operator on . We prove some new uniform weighted
resolvent estimates and also obtain some uniform Sobolev estimates associated
with the operator .Comment: Comments are welcome.To appear in Journal of Functional Analysi
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