A Sufficient Condition That J(X*) = J (X) Holds for a Banach Space X

作者：Komuro Naoto^*; Saito Kichi-Suke; Tanaka Ryotaro

来源：Tokyo Journal of Mathematics, 2018, 41(1): 219-223.

DOI：10.3836/tjm/1502179259

• James constant
• rotation invariant norm
• isosceles orthogonality

It is shown that the James constant of the space R-2 endowed with a pi/2-rotation invariant norm coincides with that of its dual space. As a corollary, we have the same statement on symmetric absolute norms on R-2.

• 出版日期2018-6