An Ostrowski Type Inequality for Convex Functions
Sever Silvestru Dragomir
TL;DR
This work extends Ostrowski-type inequalities to convex functions, establishing a sharp lower bound for the deviation between the integral mean and pointwise evaluation, and deriving a Hermite–Hadamard refinement with a sharp 1/8 constant. It then develops a composite-case framework with explicit bounds on quadrature remainder terms, and extends the analysis to integral means, providing practical bounds for mean differences and special means. The paper further demonstrates applications to probability density functions and introduces Ostrowski-type bounds for HH-divergence, yielding quantitative estimates that refine comparisons between $f$-divergence and Hermite-Hadamard divergence. Collectively, these results sharpen quadrature error estimates, link convexity-based inequalities to probabilistic and informational measures, and offer tools for analyzing divergence in information theory.
Abstract
An Ostrowski type integral inequality for convex functions and applications for quadrature rules and integral means are given. A refinement and a counterpart result for Hermite-Hadamard inequalities are obtained and some inequalities for pdf's and (HH)-divergence measure are also mentioned.
