Moduli of continuity, functional spaces,\break and elliptic boundary value problems. The full regularity spaces Cα0,λ(Ω̅)

Autor: Hugo Beirão da Veiga
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Advances in Nonlinear Analysis, Vol 7, Iss 1, Pp 15-34 (2018)
ISSN: 2191-9496
Popis: Let 𝑳 {\boldsymbol{L}} be a second order uniformly elliptic operator, and consider the equation 𝑳 ⁢ u = f {\boldsymbol{L}u=f} under the boundary condition u = 0 {u=0} . We assume data f in generical subspaces of continuous functions D ω ¯ {D_{\overline{\omega}}} characterized by a given modulus of continuity ω ¯ ⁢ ( r ) {\overline{\omega}(r)} , and show that the second order derivatives of the solution u belong to functional spaces D ω ^ {D_{\widehat{\omega}}} , characterized by a modulus of continuity ω ^ ⁢ ( r ) {\widehat{\omega}(r)} expressed in terms of ω ¯ ⁢ ( r ) {\overline{\omega}(r)} . Results are optimal. In some cases, as for Hölder spaces, D ω ^ = D ω ¯ {D_{\widehat{\omega}}=D_{\overline{\omega}}} . In this case we say that full regularity occurs. In particular, full regularity occurs for the new class of functional spaces C α 0 , λ ⁢ ( Ω ¯ ) {C^{0,\lambda}_{\alpha}(\overline{\Omega})} which includes, as a particular case, the classical Hölder spaces C 0 , λ ⁢ ( Ω ¯ ) = C 0 0 , λ ⁢ ( Ω ¯ ) {C^{0,\lambda}(\overline{\Omega})=C^{0,\lambda}_{0}(\overline{\Omega})} . Few words, concerning the possibility of generalizations and applications to non-linear problems, are expended at the end of the introduction and also in the last section.
Databáze: OpenAIRE