Sharp estimates for biorthogonal families to exponential functions associated to complex sequences without gap conditions

The general goal of this work is to obtain upper and lower bounds for the -norm of biorthogonal families to complex exponential functions associated to sequences which satisfy appropriate assumptions but without imposing a gap condition on the elements of the sequence. As a consequence, we also pres...

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Detalhes bibliográficos
Autores: González Burgos, Manuel, Ouaili, Lydia
Formato: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2023
País:España
Recursos:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/153806
Acesso em linha:https://hdl.handle.net/11441/153806
https://doi.org/10.3934/eect.2023044
Access Level:acceso abierto
Palavra-chave:Non scalar parabolic systems
null controllability
moment problem
biorthogonal families
no gap conditions
control cost
Descrição
Resumo:The general goal of this work is to obtain upper and lower bounds for the -norm of biorthogonal families to complex exponential functions associated to sequences which satisfy appropriate assumptions but without imposing a gap condition on the elements of the sequence. As a consequence, we also present new results on the cost of the boundary null controllability of two parabolic systems at time : a phase-field system and a parabolic system whose generator has eigenvalues that accumulate. In the latter case, the behavior of the control cost when goes to zero depends strongly on the accumulation parameter of the eigenvalue sequence.