On James and von Neumann-Jordan constants and sufficient conditions for the fixed point property (Q855420)

A Banach space \(X\) is said to have the fixed point property if every nonexpansive mapping \(T:C \to C\), where \(C\) is a nonempty bounded closed convex subset of \(X\), has a fixed point. It is well-known that under various geometric properties of the Banach space \(X\), often measured by different constants, the fixed point property of \(X\) is guaranteed. In the present paper, the author studies some of these constants.