关于绝对连续函数的有序巴拿赫空间上廷利问题的一个变体
A variant of Tingley's problem on ordered Banach spaces of absolutely continuous functions
AI总结:
研究关于绝对连续函数的有序巴拿赫空间上廷利问题的变体,通过定义特定空间和映射,证明满射保距映射可唯一扩展为复线性等距序同构,并得到满射相位等距映射的扩展定理。
AI中文摘要:
对于每个\(1\leq p\leq\infty\)以及\(j = 1,2\),设\(AC^p(\Omega_j)\)表示在闭单位区间\(\Omega_j = [x_j,x_j + 1]\)上复值绝对连续函数的巴拿赫空间。为其配备\(p\) - 范数\(\|f\|_{AC,p}\)以及由\(f(x_j)\geq0\)且\(f'\geq0\)几乎处处定义的序\(\geq_{AC}\)。定义\(S(AC^p(\Omega_j))^+=\{f\in AC^p(\Omega_j):\|f\|_{AC,p}=1,\ f\geq_{AC}0\}\)。证明了对于每个\(1\leq p\leq\infty\),从\(S(AC^p(\Omega_1))^+\)到\(S(AC^p(\Omega_2))^+\)的每个满射保距映射唯一地扩展为从\(AC^p(\Omega_1)\)到\(AC^p(\Omega_2)\)的复线性等距序同构。作为应用,得到了关于满射相位等距映射的相应扩展定理。
英文摘要:
For each $1\le p\le\infty$ and $j=1,2$, let $AC^p(Ω_j)$ denote the Banach space of complex-valued absolutely continuous functions on a closed unit interval $Ω_j=[x_j,x_j+1]$. We equip $AC^p(Ω_j)$ with the $p$--norm $\|f\|_{AC,p}$, and the order $\ge_{AC}$ defined by $f(x_j)\ge0$ and $f'\ge 0$ a.e. Set $$S(AC^p(Ω_j))^+=\{f\in AC^p(Ω_j):\|f\|_{AC,p}=1,\ f\ge_{AC}0\}.$$ We prove that, for each $1\le p\le\infty$, every surjective isometry $S(AC^p(Ω_1))^+\to S(AC^p(Ω_2))^+$ extends uniquely to a complex--linear isometric order isomorphism from $AC^p(Ω_1)$ onto $AC^p(Ω_2)$. As an application, we obtain a corresponding extension theorem for surjective phase--isometries.