Geometric constants and characterizations of inner product spaces
Geometric constants and characterizations of inner product spaces
Let X be a real normed space, let Ψ 2 denote the set of all convex functions on [0,1] such that max{1t,t} ψ(t) 1 , and let Φ 2 denote the set of all concave function on [0,1] such that ψ(0ψ for all nonzero vectors x, y ∈ X , …