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**Symmetric positive systems with boundary characteristic of constant multiplicity.**
*(English)*
Zbl 0549.35099

The theory of maximal positive boundary value problems for symmetric positive systems is developed assuming that the boundary is characteristic of constant multiplicity. No such hypothesis is needed on a neighbourhood of the boundary. Both regularity theorems and mixed initial boundary value problems are discussed. Many classical ideas are sharpened in the process.

### MSC:

35M99 | Partial differential equations of mixed type and mixed-type systems of partial differential equations |

35L50 | Initial-boundary value problems for first-order hyperbolic systems |

35B30 | Dependence of solutions to PDEs on initial and/or boundary data and/or on parameters of PDEs |

35A05 | General existence and uniqueness theorems (PDE) (MSC2000) |

35A30 | Geometric theory, characteristics, transformations in context of PDEs |

### Keywords:

characteristic boundary; dissipative boundary conditions; mixed initial- boundary value problem; maximal positive boundary value problems; symmetric positive systems; constant multiplicity; regularity
Full Text:
DOI

### References:

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