3 papers
math.FA2025
Old and New on Strongly Subadditive/Superadditive Functions
Constantin P. Niculescu
In this paper we provide insight into the classes of strongly subadditive/superadditive functions by highlighting numerous new examples and new results.
math.FA2024
Functional inequalities in the framework of Banach spaces
Constantin P. Niculescu
A quadrilateral inequality established by C. Schötz in the context of Hilbert spaces is extended to the framework of Banach spaces. Our approach is based on the majorization theor…
math.CA2024
A survey of the Hornich-Hlawka inequality
Dan-Åtefan Marinescu, Constantin P. Niculescu
In this survey, we review the many faces of the Hornich-Hlawka inequality. Several open problems that seem of utmost interest are mentioned.