Optimal three-ball inequalities and quantitative uniqueness for the Stokes system
Ching-Lung Lin - Department of Mathematics, NCTS, National Cheng Kung University, Tainan 701, Taiwan (email)
Abstract: We study the local behavior of a solution to the Stokes system with singular coefficients in $R^n$ with $n=2,3$. One of our main results is a bound on the vanishing order of a nontrivial solution $u$ satisfying the Stokes system, which is a quantitative version of the strong unique continuation property for $u$. Different from the previous known results, our strong unique continuation result only involves the velocity field $u$. Our proof relies on some delicate Carleman-type estimates. We first use these estimates to derive crucial optimal three-ball inequalities for $u$. Taking advantage of the optimality, we then derive an upper bound on the vanishing order of any nontrivial solution $u$ to the Stokes system from those three-ball inequalities. As an application, we derive a minimal decaying rate at infinity of any nontrivial $u$ satisfying the Stokes equation under some a priori assumptions.
Keywords: Optimal three-ball inequalities, Carleman estimates, Stokes system.
Received: April 2010; Published: April 2010.
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