An orthogonality relation in complex normed spaces based on norm derivatives

S. M. Enderami, M. Abtahi, A. Zamani +1

Let $X$ be a complex normed space. Based on the right norm derivative ${\rho }_{{}_{+}}$, we define a mapping ${\rho }_{{}_{\infty }}$ by \begin{equation*} ρ_{_{\infty}}(x,y) = \frac1π\int_0^{2π}e^…