论文标题
定量约翰·尼伦贝格(John-Nirenberg)的不平等现象
Quantitative John-Nirenberg inequalities at different scales
论文作者
论文摘要
我们提供了表格的抽象估计\ [ \ | f-f_ {q,μ} \ | _ {x \ left(q,\ frac {\ mathrm {d}μ} {y(q)} \ right)} \ leq c(μ) \ \]对于所有立方体,$ \ Mathbb {r}^n $和每个功能$ f \ in \ mathrm {bmo}(\ Mathrm {d}μ)$,其中$μ$是$ \ alsbb {r}^n $,$ y $ y Mathbb {r}^n $,$ y $的倍增度,是$ \ y $ y $ y $ y $ cy \ y \ cy \ cudy | cus y | \ left(q,\ frac {\ mathrm {d} w} {w(q)} \ right)} $是一个足够好的准准分子,$ c(μ,y)$和$ψ(x)$是正值的,分别取决于$μ$和$ y $,以及$ y $,以及$ x $。该抽象方案使我们能够恢复尖锐的估计\ [ \ | f-f_ {q,μ} \ | _ {l^p \ left(q,q,\ frac {\ mathrm {d}μ(x)} {μ(q)} \ right)} \ leq c(q)} \ leq c(μ) \ qquad p \ geq1 \]对于每个立方体$ q $和\ mathrm {bmo}(\ mathrm {d}μ)$中的每个$ f \ in \ qquad p \ geq1 \] $等同于约翰 - 尼伦贝格的不平等,也使我们能够获得$ l^p $ replative&replative&reppers&quofe l^p $,并且在$ like po p $ po $时,$ f \ quq1 \ geq1 \]。 $ l^{p(\ cdot)} $ spaces。 除了上述结果,我们还将[OPRRR20]中的定理1.2推广到倍增度量的设置,并获得了Muckenhoupt的$ a_ \ iftty $ striges的新表征。
We provide an abstract estimate of the form \[ \|f-f_{Q,μ}\|_{X \left(Q,\frac{\mathrm{d} μ}{Y(Q)}\right)}\leq c(μ,Y)ψ(X)\|f\|_{\mathrm{BMO}(\mathrm{d}μ)} \] for all cubes $Q$ in $\mathbb{R}^n$ and every function $f\in \mathrm{BMO}(\mathrm{d}μ)$, where $μ$ is a doubling measure in $\mathbb{R}^n$, $Y$ is some positive functional defined on cubes, $\|\cdot \|_{X \left(Q,\frac{\mathrm{d} w}{w(Q)}\right)}$ is a sufficiently good quasi-norm and $c(μ,Y)$ and $ψ(X)$ are positive constants depending on $μ$ and $Y$, and $X$, respectively. That abstract scheme allows us to recover the sharp estimate \[ \|f-f_{Q,μ}\|_{L^p \left(Q,\frac{\mathrm{d} μ(x)}{μ(Q)}\right)}\leq c(μ)p\|f\|_{\mathrm{BMO}(\mathrm{d}μ)}, \qquad p\geq1 \] for every cube $Q$ and every $f\in \mathrm{BMO}(\mathrm{d}μ)$, which is known to be equivalent to the John-Nirenberg inequality, and also enables us to obtain quantitative counterparts when $L^p$ is replaced by suitable strong and weak Orlicz spaces and $L^{p(\cdot)}$ spaces. Besides the aforementioned results we also generalize Theorem 1.2 in [OPRRR20] to the setting of doubling measures and obtain a new characterization of Muckenhoupt's $A_\infty$ weights.