On Marginal Subgradients of Convex Functions
For a lower semicontinuous and proper convex function f with nonempty minimizer set and a point x in its domain, a marginal subgradient of f at x is a vector in df(x) with the smallest norm. We denote the norm of the marginal subgradient of f at x by g(x), it is known that the infimum of g(x) over a level set of f is nondecreasing from a lower level set to a higher level set. In this paper we study another aspect of the marginal subgradients, namely the monotonicity of the infimum of g(x) over an equidistance contour from the minimizer set. The results are applied to the study of some growth properties of the marginal subgradients.
Roxin Zhang
Department of Mathematics and Computer Science Northern Michigan University Marquette,Ml 49855,USA
国际会议
黄山
英文
90-93
2010-05-28(万方平台首次上网日期,不代表论文的发表时间)