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Lipschitz stability in the determination of the principal part of a parabolic equation

Ganghua Yuan, Masahiro Yamamoto (2009)

ESAIM: Control, Optimisation and Calculus of Variations

Let y ( h ) ( t , x ) be one solution to t y ( t , x ) - i , j = 1 n j ( a i j ( x ) i y ( t , x ) ) = h ( t , x ) , 0 < t < T , x Ω with a non-homogeneous term h , and y | ( 0 , T ) × Ω = 0 , where Ω n is a bounded domain. We discuss an inverse problem of determining n ( n + 1 ) / 2 unknown functions a i j by { ν y ( h ) | ( 0 , T ) × Γ 0 , y ( h ) ( θ , · ) } 1 0 after selecting input sources h 1 , . . . , h 0 suitably, where Γ 0 is an arbitrary subboundary, ν denotes the normal derivative, 0 < θ < T and 0 . In the case of 0 = ( n + 1 ) 2 n / 2 , we prove the Lipschitz stability in the inverse problem if we choose ( h 1 , . . . , h 0 ) from a set { C 0 ( ( 0 , T ) × ω ) } 0 with an arbitrarily fixed subdomain ω Ω . Moreover we can take 0 = ( n + 3 ) n / 2 by making special choices for h , 1 0 . The proof is...

Lipschitz stability in the determination of the principal part of a parabolic equation

Ganghua Yuan, Masahiro Yamamoto (2008)

ESAIM: Control, Optimisation and Calculus of Variations

Let y(h)(t,x) be one solution to t y ( t , x ) - i , j = 1 n j ( a i j ( x ) i y ( t , x ) ) = h ( t , x ) , 0 < t < T , x Ω with a non-homogeneous term h, and y | ( 0 , T ) × Ω = 0 , where Ω n is a bounded domain. We discuss an inverse problem of determining n(n+1)/2 unknown functions aij by { ν y ( h ) | ( 0 , T ) × Γ 0 , y ( h ) ( θ , · ) } 1 0 after selecting input sources h 1 , . . . , h 0 suitably, where Γ 0 is an arbitrary subboundary, ν denotes the normal derivative, 0 < θ < T and 0 . In the case of 0 = ( n + 1 ) 2 n / 2 , we prove the Lipschitz stability in the inverse problem if we choose ( h 1 , . . . , h 0 ) from a set { C 0 ( ( 0 , T ) × ω ) } 0 with an arbitrarily fixed subdomain ω Ω . Moreover we can take 0 = ( n + 3 ) n / 2 by making special choices for...

Long time dynamics for the one dimensional non linear Schrödinger equation

Nicolas Burq, Laurent Thomann, Nikolay Tzvetkov (2013)

Annales de l’institut Fourier

In this article, we first present the construction of Gibbs measures associated to nonlinear Schrödinger equations with harmonic potential. Then we show that the corresponding Cauchy problem is globally well-posed for rough initial conditions in a statistical set (the support of the measures). Finally, we prove that the Gibbs measures are indeed invariant by the flow of the equation. As a byproduct of our analysis, we give a global well-posedness and scattering result for the L 2 critical and super-critical...

Lp estimates for degenerate elliptic equations.

Antonio Sánchez-Calle (1988)

Revista Matemática Iberoamericana

In this note we are going to address the question of when a second order differential operator is controlled by a subelliptic second order differential operator.

Lyapunov functions and L p -estimates for a class of reaction-diffusion systems

Dirk Horstmann (2001)

Colloquium Mathematicae

We give a sufficient condition for the existence of a Lyapunov function for the system aₜ = ∇(k(a,c)∇a - h(a,c)∇c), x ∈ Ω, t > 0, ε c = k c Δ c - f ( c ) c + g ( a , c ) , x ∈ Ω, t > 0, for Ω N , completed with either a = c = 0, or ∂a/∂n = ∂c/∂n = 0, or k(a,c) ∂a/∂n = h(a,c) ∂c/∂n, c = 0 on ∂Ω × t > 0. Furthermore we study the asymptotic behaviour of the solution and give some uniform L p -estimates.

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