On the Symmetrizations of $\varepsilon$-Isometries on Positive Cones of Continuous Function Spaces
Funkcionalʹnyj analiz i ego priloženiâ, Tome 55 (2021) no. 1, pp. 93-97
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Let $K$ be a compact Hausdorff space, $C(K)$ be the real Banach space of all continuous functions on $K$ endowed with the supremum norm,
and $C(K)^+$ be the positive cone of $C(K)$. A weak stability result for the symmetrization $\Theta=(f(\,\boldsymbol\cdot\,)-f(-\;\boldsymbol\cdot\,)/2$ of a general $\varepsilon$-isometry $f$ from $C(K)^+\cup-C(K)^+$ to a Banach space $Y$
is obtained: For any element $k\in K$, there exists a $\phi\in S_{Y^\ast}$ such that
\begin{equation*}
|\langle\delta_k,x\rangle-\langle\phi,\Theta(x)\rangle|\le3\varepsilon/2\quad\text{for
all }\,x\in C(K)^+\cup-C(K)^+.
\end{equation*}
This result is used to prove new stability theorems for the symmetrization $\Theta$ of $f$.
Keywords:
symmetrization of $\varepsilon$-isometry, stability, function space.
@article{FAA_2021_55_1_a7,
author = {Longfa Sun},
title = {On the {Symmetrizations} of $\varepsilon${-Isometries} on {Positive} {Cones} of {Continuous} {Function} {Spaces}},
journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
pages = {93--97},
publisher = {mathdoc},
volume = {55},
number = {1},
year = {2021},
language = {ru},
url = {http://geodesic.mathdoc.fr/item/FAA_2021_55_1_a7/}
}
TY - JOUR AU - Longfa Sun TI - On the Symmetrizations of $\varepsilon$-Isometries on Positive Cones of Continuous Function Spaces JO - Funkcionalʹnyj analiz i ego priloženiâ PY - 2021 SP - 93 EP - 97 VL - 55 IS - 1 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/FAA_2021_55_1_a7/ LA - ru ID - FAA_2021_55_1_a7 ER -
Longfa Sun. On the Symmetrizations of $\varepsilon$-Isometries on Positive Cones of Continuous Function Spaces. Funkcionalʹnyj analiz i ego priloženiâ, Tome 55 (2021) no. 1, pp. 93-97. http://geodesic.mathdoc.fr/item/FAA_2021_55_1_a7/