The generalized sine function and geometrical properties of normed spaces

Let \((X,\|\cdot\|)\) be a normed space. We deal here with a function \(s:X\times X\to\mathbb{R}\) given by the formula \[s(x,y):=\inf_{\lambda\in\mathbb{R}}\frac{\|x+\lambda y\|}{\|x\|}\] (for \(x=0\) we must define it separately). Then we take two unit vectors \(x\) and \(y\) such that \(y\) is or...

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Bibliographic Details
Main Author: Tomasz Szostok
Format: Article
Language:English
Published: AGH Univeristy of Science and Technology Press 2015-01-01
Series:Opuscula Mathematica
Subjects:
Online Access:http://www.opuscula.agh.edu.pl/vol35/1/art/opuscula_math_3508.pdf