Cheng, Li Xin et Teng, Yan Mei, Certain Subsets on Which Every Bounded Convex Function Is Continuous, Acta mathematica Sinica. English series (Print) , 23(6), 2007, pp. 1063-1066
To guarantee every real-valued convex function bounded above on a set is continuous, how .thick. should the set be? For a symmetric set A in a Banach space E, the answer of this paper is: Every real-valued convex function bounded above on A is continuous on E if and only if the following two conditions hold: i) spanA has finite co-dimentions and ii) coA has nonempty relative interior. This paper also shows that a subset A . E satisfying every real-valued convex function bounded above on A is continuous on E if (and only if) every real-valued linear functional bounded above on A is continuous on E, which is also equivalent to that every real-valued convex function bounded on A is continuous on E.