Semilinear formulation of a hyperbolic system of partial differential equations

In this paper, we solve the Cauchy problem for a hyperbolic system of first-order PDEs defined on a certain Banach space X. The system has a special semilinear structure because, on the one hand, the evolution law can be expressed as the sum of a linear unbounded operator and a nonlinear Lipschitz f...

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Detalles Bibliográficos
Autores: Barril, Carles|||0000-0002-4612-5533, Calsina i Ballesta, Àngel|||0000-0003-2585-0039
Tipo de recurso: artículo
Fecha de publicación:2022
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:264430
Acceso en línea:https://ddd.uab.cat/record/264430
https://dx.doi.org/urn:doi:10.1007/s00028-022-00816-4
Access Level:acceso abierto
Palabra clave:Semilinear hyperbolic systems
Sun dual formulation
Linearization principle
Spectral mapping theorem
Spatially structured populations
Descripción
Sumario:In this paper, we solve the Cauchy problem for a hyperbolic system of first-order PDEs defined on a certain Banach space X. The system has a special semilinear structure because, on the one hand, the evolution law can be expressed as the sum of a linear unbounded operator and a nonlinear Lipschitz function but, on the other hand, the nonlinear perturbation takes values not in X but on a larger space Y which is related to X. In order to deal with this situation we use the theory of dual semigroups. Stability results around steady states are also given when the nonlinear perturbation is Fréchet differentiable. These results are based on two propositions: one relating the local dynamics of the nonlinear semiflow with the linearised semigroup around the equilibrium, and a second relating the dynamical properties of the linearised semigroup with the spectral values of its generator. The later is proven by showing that the Spectral Mapping Theorem always applies to the semigroups one obtains when the semiflow is linearised. Some epidemiological applications involving gut bacteria are commented.