Superquadratic functions in several variables

The concept of superquadratic functions in several variables, as a generalization of the same concept in one variable is introduced. Analogous results to results obtained for convex functions in one and several variables are presented. These include refinements of Jensen’s inequality and its counterpart, and of Slater– Peˇcari´c’s inequality. © 2006 Elsevier Inc. All rights reserved