Null controllability properties of some degenerate parabolic equations.
Null controllability properties of some degenerate parabolic equations.
Null controllability properties of some degenerate parabolic equations.
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Associated observability estimate<br />
The null <strong>controllability</strong> result derives from the following<br />
observability estimate :<br />
Theorem<br />
Under (H s (A)), there is <strong>some</strong> C(Ω, ω, T ) independent <strong>of</strong> α ∈ [0, 1)<br />
such that, given v T ∈ L 2 (Ω), the solution v <strong>of</strong> the adjoint problem<br />
satisfies :<br />
∫<br />
Ω<br />
⎧<br />
⎪⎨ v t + div (A(x)∇v) = 0, x ∈ Ω, t > 0<br />
v(t, x) = 0 on Γ,<br />
⎪⎩<br />
v(T , x) = v T (x)<br />
∫ T ∫<br />
v(0, x) 2 dx ≤ C(Ω, ω, T ) v(t, x) 2 dx dt.<br />
0 ω<br />
Hence : usual observability estimate, but in the <strong>degenerate</strong> context.<br />
11/26