Spaces of generalized smoothness in the critical case: Optimal embeddings, continuity envelopes and approximation numbers

Autor: Júlio S. Neves, Susana D. Moura, Cornelia Schneider
Rok vydání: 2014
Předmět:
Zdroj: Repositório Científico de Acesso Aberto de Portugal
Repositório Científico de Acesso Aberto de Portugal (RCAAP)
instacron:RCAAP
ISSN: 0021-9045
DOI: 10.1016/j.jat.2014.07.010
Popis: We study necessary and sufficient conditions for embeddings of Besov spaces of generalized smoothness B p , q ? , N ( R n ) into generalized Holder spaces ? ∞ , r µ ( ? ) ( R n ) when s ? ( N ? - 1 ) 0 and ? - 1 ? ? q ' , where ? = ? N - n / p . A borderline situation, corresponding to the limiting situation in the classical case, is included and give new results. In particular, we characterize optimal embeddings for B -spaces.As immediate applications of our results we obtain continuity envelopes and give upper and lower estimates for approximation numbers for the related embeddings.We also consider the analogous results for the Triebel-Lizorkin spaces of generalized smoothness F p , q ? , N ( R n ) .
Databáze: OpenAIRE