2,140 research outputs found

    Recovery of time-dependent damping coefficients and potentials appearing in wave equations from partial data

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    We consider the inverse problem of determining a time-dependent damping coefficient aa and a time-dependent potential qq, appearing in the wave equation ∂t2u−Δxu+a(t,x)∂tu+q(t,x)u=0\partial_t^2u-\Delta_x u+a(t,x)\partial_tu+q(t,x)u=0 in Q=(0,T)×ΩQ=(0,T)\times\Omega, with T>0T>0 and Ω\Omega a C2 \mathcal C^2 bounded domain of Rn\mathbb R^n, n≥2n\geq2, from partial observations of the solutions on ∂Q\partial Q. More precisely, we look for observations on ∂Q\partial Q that allow to determine uniquely a large class of time-dependent damping coefficients aa and time-dependent potentials qq without involving an important set of data. We prove global unique determination of a∈W1,p(Q)a\in W^{1,p}(Q), with p>n+1p>n+1, and q∈L∞(Q)q\in L^\infty(Q) from partial observations on ∂Q\partial Q

    Determination of singular time-dependent coefficients for wave equations from full and partial data

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    We study the problem of determining uniquely a time-dependent singular potential qq, appearing in the wave equation ∂t2u−Δxu+q(t,x)u=0\partial_t^2u-\Delta_x u+q(t,x)u=0 in Q=(0,T)×ΩQ=(0,T)\times\Omega with T>0T>0 and Ω\Omega a C2 \mathcal C^2 bounded domain of Rn\mathbb R^n, n≥2n\geq2. We start by considering the unique determination of some singular time-dependent coefficients from observations on ∂Q\partial Q. Then, by weakening the singularities of the set of admissible coefficients, we manage to reduce the set of data that still guaranties unique recovery of such a coefficient. To our best knowledge, this paper is the first claiming unique determination of unbounded time-dependent coefficients, which is motivated by the problem of determining general nonlinear terms appearing in nonlinear wave equations

    Stability in the determination of a time-dependent coefficient for wave equations from partial data

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    We consider the stability in the inverse problem consisting of the determination of a time-dependent coefficient of order zero qq, appearing in a Dirichlet initial-boundary value problem for a wave equation ∂t2u−Δu+q(t,x)u=0\partial_t^2u-\Delta u+q(t,x)u=0 in Q=(0,T)×ΩQ=(0,T)\times\Omega with Ω\Omega a C2C^2 bounded domain of Rn\mathbb R^n, n≥2n\geq2, from partial observations on ∂Q\partial Q. The observation is given by a boundary operator associated to the wave equation. Using suitable complex geometric optics solutions and Carleman estimates, we prove a stability estimate in the determination of qq from the boundary operator

    Partial data inverse problem for hyperbolic equation with time-dependent damping coefficient and potential

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    We study an inverse problem of determining time-dependent damping coefficient and potential appearing in the wave equation in a compact Riemannian manifold of dimension three or higher. More specifically, we are concerned with the case of conformally transversally anisotropic manifolds, or in other words, compact Riemannian manifolds with boundary conformally embedded in a product of the Euclidean line and a transversal manifold. With an additional assumption of the attenuated geodesic ray transform being injective on the transversal manifold, we prove that the knowledge of a certain partial Cauchy data set determines time-dependent damping coefficient and potential uniquely.Comment: arXiv admin note: text overlap with arXiv:1702.07974 by other author

    Stability estimate in an inverse problem for non-autonomous Schr\"odinger equations

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    We consider the inverse problem of determining the time dependent magnetic field of the Schr\"odinger equation in a bounded open subset of RnR^n, with n≥1n \geq 1, from a finite number of Neumann data, when the boundary measurement is taken on an appropriate open subset of the boundary. We prove the Lispchitz stability of the magnetic potential in the Coulomb gauge class by nn times changing initial value suitably
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