English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We study the periodic boundary value problem associated with the second ordernonlinear equation \begin{equation*} u'' + ( \lambda a^{+}(t) - \mu a^{-}(t) )g(u) = 0, \end{equation*} where $g(u)$ has superlinear growth at zero andsublinear growth at infinity. For $\lambda, \mu$ positive and large, we provethe existence of $3^{m}-1$ positive $T$-periodic solutions when the weightfunction $a(t)$ has $m$ positive humps separated by $m$ negative ones (in a$T$-periodicity interval). As a byproduct of our approach we also provideabundance of positive subharmonic solutions and symbolic dynamics. The proof isbased on coincidence degree theory for locally compact operators on openunbounded sets and also applies to Neumann and Dirichlet boundary conditions.Finally, we deal with radially symmetric positive solutions for the Neumann andthe Dirichlet problems associated with elliptic PDEs.

Positive solutions for super-sublinear indefinite problems: high multiplicity results via coincidence degree