2014/03/20 by Federico Cacciafesta, Cacciafesta, Federico, Piero DʼAncona +4 · 1 citation
Computer Science · Mathematics · #Advanced Harmonic Analysis Research #Advanced Mathematical Modeling in Engineering #Advanced Mathematical Physics Problems #Analysis of PDEs (math.AP) #FOS: Mathematics #FOS: Physical sciences #Mathematical Physics (math-ph) #Numerical methods in inverse problems
paper · pdf · doi:10.48550/arxiv.1403.5288
openalex publication_date 2014/03/20 · openalex created_date 2025/10/24 · openalex updated_date 2026/07/28
We prove smoothing estimates in Morrey-Campanato spaces for a Helmholtz\nequation \n -Lu+zu=f,\n
qquad\n -Lu:=
nablab(a(x)
nablabu)-c(x)u,\n
qquad\n
nablab:=
nabla+ib(x) with fully variable coefficients, of limited\nregularity, defined on the exterior of a starshaped compact obstacle in\n\ℝn, n\≥3, with Dirichlet boundary conditions. The principal\npart of the operator is a long range perturbation of a constant coefficient\noperator, while the lower order terms have an almost critical decay. We give\nexplicit conditions on the size of the perturbation which prevent trapping.\n As an application, we prove smoothing estimates for the Schr "odinger flow\neitL and the wave flow eit \√(L) with variable coefficients on\nexterior domains and Dirichlet boundary conditions.\n