It's well known that a closed convex set in a finite-dimensional normed space is unbounded if and only if it has a nonzero recession direction. In this work, we shall prove that in every infinite-dimensional normed space there exists an unbounded closed convex set whose recession cone consists of the zero vector alone.
机构:
Lomonosov Moscow State Univ, Moscow 119991, Russia
Moscow Ctr Fundamental & Appl Math, Moscow 119991, RussiaLomonosov Moscow State Univ, Moscow 119991, Russia