Symmetrisers and generalised solutions for strictly hyperbolic systems with singular coefficients |
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| Authors: | Claudia Garetto Michael Oberguggenberger |
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| Affiliation: | 1. Department of Mathematical Sciences, Loughborough University, Loughborough, UK;2. +43 512 507 61300+43 512 507 61399;3. Unit of Engineering Mathematics, University of Innsbruck, Innsbruck, Austria |
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| Abstract: | This paper is devoted to strictly hyperbolic systems and equations with non‐smooth coefficients. Below a certain level of smoothness, distributional solutions may fail to exist. We construct generalised solutions in the Colombeau algebra of generalised functions. Extending earlier results on symmetric hyperbolic systems, we introduce generalised strict hyperbolicity, construct symmetrisers, prove an appropriate Gårding inequality and establish existence, uniqueness and regularity of generalised solutions. Under additional regularity assumptions on the coefficients, when a classical solution of the Cauchy problem (or of a transmission problem in the piecewise regular case) exists, the generalised solution is shown to be associated with the classical solution (or the piecewise classical solution satisfying the appropriate transmission conditions). |
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| Keywords: | Hyperbolic systems algebras of generalised functions non‐smooth coefficients symmetriser Primary: 35S30 Secondary: 46F30 |
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