Anomalous self-similar solutions of exponential type for the subcritical fast diffusion equation with weighted reaction

We prove existence and uniqueness of the branch of the so-called anomalous eternal solutions in exponential self-similar form for the subcritical fast-diffusion equation with a weighted reaction term ∂ t u = Δ u m + | x | σ u p , posed in R N with N ⩾ 3, where 1,$> 0 < m < m c = N − 2 N , p...

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Detalhes bibliográficos
Autores: Sanchez, Ariel, Iagar, Razvan Gabriel
Tipo de documento: artigo
Data de publicação:2022
País:España
Recursos:Universidad Rey Juan Carlos
Repositório:BURJC-Digital. Repositorio Institucional de la Universidad Rey Juan Carlos
OAI Identifier:oai:burjcdigital.urjc.es:10115/29838
Acesso em linha:https://hdl.handle.net/10115/29838
Access Level:Acceso aberto
Palavra-chave:anomalous solutions
fast diffusion equation
exponential self-similar solutions
weighted reaction
phase plane analysis
critical exponents
Descrição
Resumo:We prove existence and uniqueness of the branch of the so-called anomalous eternal solutions in exponential self-similar form for the subcritical fast-diffusion equation with a weighted reaction term ∂ t u = Δ u m + | x | σ u p , posed in R N with N ⩾ 3, where 1,$> 0 < m < m c = N − 2 N , p > 1 , and the critical value for the weight σ = 2 ( p − 1 ) 1 − m . The branch of exponential self-similar solutions behaves similarly as the well-established anomalous solutions to the pure fast diffusion equation, but without a finite time extinction or a finite time blow-up, and presenting instead a change of sign of both self-similar exponents at m = m s = ( N − 2)/( N + 2), leading to surprising qualitative differences. In this sense, the reaction term we consider realizes a perfect equilibrium in the competition between the fast diffusion and the reaction effects.