Von Neumann constant for weak Orlicz spaces and weak Lebesgue spaces.

In this paper we give some lower bounds of von Neumann-Jordan constant for weak Orlicz spaces and weak Lebesgue spaces. As an application, we prove that the von Neumann-Jordan constant for the weak Lebesgue space wLp tends to 2 as p tends to infinity. Our proof uses the refinement of the positive constant in the triangle inequality in wLp. [ABSTRACT FROM AUTHOR]