AI 中文总结
该研究肯定回答了Aliaga的问题,证明特定序列乘积上的无Lipschitz空间同构于ℱ(ℤᵈ),推广了非实常数多项式情形的结论。
AI 中文摘要
我们肯定地回答了Aliaga提出的一个问题,证明对任意非实常数多项式p,集合{(p(n), p(m)):n, m∈ℕ}上的无Lipschitz空间同构于ℱ(ℤ²)。我们更一般地证明:若d∈ℕ、q∈ℤ≥0,序列((aₙ⁽ⁱ⁾)ₙ=1^∞)ᵢ=1^d与((bₘ⁽ʲ⁾)ₘ=1^∞)ⱼ=1^q满足0<a₁⁽ⁱ⁾<a₂⁽ⁱ⁾<…、0<b₁⁽ʲ⁾<b₂⁽ʲ⁾<…,aₙ⁽ⁱ⁾→∞(n→∞),aₙ₊₁⁽ⁱ⁾/aₙ⁽ⁱ⁾→1(n→∞),且对所有i,j有liminfₘ→∞ bₘ₊₁⁽ʲ⁾/bₘ⁽ʲ⁾>1,则这些d+q个序列乘积上的无Lipschitz空间同构于ℱ(ℤᵈ)。
英文摘要
We answer positively a question of Aliaga and show that for any nonconstant real polynomial $p$, the Lipschitz-free space over $\{(p(n), p(m)):n, m\in \mathbb{N}\}$ is isomorphic to $\mathcal{F}(\mathbb{Z}^2)$. We in fact show more generally that if $d\in \mathbb{N}$, $q\in \mathbb{Z}_{\geq 0}$, and $((a_n^{(i)})_{n=1}^\infty)_{i=1}^d$, $((b_m^{(j)})_{m=1}^\infty)_{j=1}^q$ are sequences with $0<a_1^{(i)}<a_2^{(i)}<\cdots$, $0<b_1^{(j)}<b_2^{(j)}<\cdots$, $a_n^{(i)}\to \infty$ as $n\to \infty$, $\frac{a_{n+1}^{(i)}}{a_n^{(i)}}\to 1$ as $n\to \infty$ and $\underset{m\to \infty}{\liminf}{\frac{b_{m+1}^{(j)}}{b_m^{(j)}}}>1$ for all $i, j$, then the Lipschitz-free space over the product of these $d+q$ sequences is isomorphic to $\mathcal{F}(\mathbb{Z}^d)$.
Comments15 pages