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数学物理学报, 2018, 38(6): 1067-1075 doi:

论文

变量核Marcinkiewicz积分及其交换子在变指标Morrey空间上的有界性

邵旭馗,1, 陶双平2

Boundedness of Marcinkiewicz Integrals and Commutators with Variable Kernel on Morrey Spaces with Variable Exponents

Shao Xukui,1, Tao Shuangping2

通讯作者: 邵旭馗, E-mail: shwangsp@126.com

收稿日期: 2017-05-24  

基金资助: 国家自然科学基金.  11561062
甘肃省高等学校科研项目.  2017A-100

Received: 2017-05-24  

Fund supported: the NSFC.  11561062
the College Scientific Research Project of Gansu Province.  2017A-100

摘要

利用变量核Marcinkiewicz积分算子μΩ在变指标Lebesgue空间上的有界性,证明了它们在变指标Morrey空间上的有界性.同时还得到了由μΩ与BMO函数b生成的交换子μΩb在变指标Morrey空间上的估计.

关键词: Marcinkiewicz积分 ; 变指标Morrey空间 ; Rn)空间]]> ; 变量核

Abstract

In this paper, we using the boundednes results of Marcinkiewicz integrals with variable kernels μΩ and their commutators μΩb which generated by μΩ and BMO function b on Lebesgue spaces with variable exponents, the boundednes results are established on Morrey spaces with variable exponents..

Keywords: Marcinkiewicz integrals ; Morrey spaces with variable exponent ; Rn) ]]> ; Variable kernel

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本文引用格式

邵旭馗, 陶双平. 变量核Marcinkiewicz积分及其交换子在变指标Morrey空间上的有界性. 数学物理学报[J], 2018, 38(6): 1067-1075 doi:

Shao Xukui, Tao Shuangping. Boundedness of Marcinkiewicz Integrals and Commutators with Variable Kernel on Morrey Spaces with Variable Exponents. Acta Mathematica Scientia[J], 2018, 38(6): 1067-1075 doi:

1 引言及主要结果

Sn1Rn(n2)中的单位球面,其上的Lebesgue测度用dσ=dσ(x)表示.设函数Ω(x,z)满足

Ω(x,λz)=Ω(x,z),  x,zRn,λ>0
(1.1)

与消失条件

Sn1Ω(x,z)d(z)=0,  xRn,z=zz,  zRn{0}.
(1.2)

变量核Marcinkiewicz积分μΩ定义为

μΩ(f)(x)=(0|FΩ,t(x)|2dtt3)1/2,
(1.3)

其中

FΩ,t(x)=|xy|tΩ(x,xy)|xy|n1f(y)dy.

bBMO(Rn),变量核Marcinkiewicz积分交换子μbΩ(f)定义为

μbΩ(f)(x)=(0||xy|tΩ(x,xy)|xy|n1[b(x)b(y)]f(y)dy|2dtt3)1/2.
(1.4)

Stein[1]首先证明了当Ω(z)=Ω(x,z)满足ΩLipα(Sn1)(0<α1)时, Marcinkiewicz积分μΩ(p,p)(1<p2)和弱(1,1)型的.这里ΩLipα(Sn1)(0<α1)是指,存在一个常数C,使得

|Ω(x,y)Ω(x,z)|C|yz|α,y,zSn1.
(1.5)

Calderón等[2]考虑了带变量核的奇异积分算子TΩLp有界性.他们发现这类算子与变系数的二阶线性椭圆方程密切相关.近年来,关于变量核奇异积分算子的有界性受到了人们的广泛关注,例如, Ding等[3]得到了带变量核的Marcinkiewicz积分算子的Lp有界性; Tao等[4]证明了带变量核的Marcinkiewicz积分算子在齐次Morrey-Herz空间上的有界性;有关变量核Marcinkiewicz积分的相关结果见文献[5-6].

2006年, Cruz-Uribe等[7]证明了只要Hardy-Littlewood极大算子在变指标Lq()上有界,调和分析中的很多经典算子,如极大算子、奇异积分算子等等都是有界的. 2012年, Wang, Fu和Liu[8]得到了高阶Marcinkiewicz积分交换子在变指标Lebesgue空间上的有界性.Liu和Wang[9]考虑了Marcinkiewicz积分μΩ及其交换子在变指标Herz空间上的有界性.Tao等[10]证明了Marcinkiewicz积分μΩ及其交换子在变指标Morrey空间上的有界性,最近, Wang和Xu[11]又得到了多线性Calderón-Zygmund算子及其与BMO函数生成的交换子在变指标Morrey空间上的有界性,受以上研究的启发,本文的主要目的是研究带变量核的Marcinkiewicz积分μΩ以及由μΩ与BMO函数b生成的交换子μbΩ在变指标Morrey空间上的有界性.

首先给出一些定义与记号.

kZ,记Bk=B(0,2k)={xRn:|x|2k},及Ck=BkBk1,并记χk=χCk为集Ck的特征函数.

定义1.1 给定一个可测函数q():Rn[1,),设f是可测函数,对某个η>0,变指标Lebesgue空间Lq()(Rn)定义如下

Lq()(Rn)={f:Rn(|f(x)|η)q()dx<,η>0},

其范数为

易见,如果q(\cdot)=q_{0}是常数,那么L^{q(\cdot)}({\Bbb R}^n)成为标准的Lebesgue空间L^{q_{0}}({\Bbb R}^n).

{\cal P}({\Bbb R}^n)=\{q(\cdot):1<q_{-}, q^{+}<\infty\}.

{\cal B}({\Bbb R}^n)表示使得Hardy-Littlewood极大算子在L^{q(\cdot)}({\Bbb R}^n)上有界的所有{\cal P}({\Bbb R}^n)中的函数q(\cdot)构成的集合[7].

定义1.2[12] 设q\in L^{\infty}并且1<q(\cdot)\leq\infty, 若存在一个常数C,使得对任意的x\in{\Bbb R}^nr>0,可测函数u(x, r):{\Bbb R}^n\times(0, \infty)\rightarrow(0, \infty)满足

\mathop \sum \limits_{j = 0}^\infty \frac{\|\chi_{B(x, r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}}{\|\chi_{B(x, 2^{j+1}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}}u(x, 2^{j+1}r)<C u(x, r),
(1.6)

则称u(x, r)L^{q(\cdot)}({\Bbb R}^n)上的一个Morrey权函数.用{\Bbb W}_{q(\cdot)}来表示Morrey权函数类.

定义1.3[12] 设q(\cdot)\in {\cal P}({\Bbb R}^n), u(x, r)\in{\Bbb W}_{q(\cdot)},变指标Morrey空间定义为

{\cal M}_{q(\cdot), u}({\Bbb R}^n)=\bigg\{f:\|f\|_{{\cal M}_{q(\cdot), u}}=\sup\limits_{z\in{\Bbb R}^n, r>0}\frac{1}{u(z, r)}\|\chi_{B(z, r)}f\|_{L^{q(\cdot)}({\Bbb R}^n)}<\infty\bigg\}.

容易看出,当\lambda, q为常数,且u(x, r)=r^{\lambda}, 0\leq\lambda<n, q(\cdot)=q时,变指标的Morrey空间{\cal M}_{q(\cdot), u}({\Bbb R}^n)就是经典的Morrey空间M_{q, \lambda}({\Bbb R}^n).

BMO空间定义如下

{\rm BMO}({\Bbb R}^n)=\bigg\{b\in L^{1}_{{\rm loc}}({\Bbb R}^n):\|b\|_{{\rm BMO}({\Bbb R}^n)}:=\sup\limits_{Q\subset{\Bbb R}^n}\frac{1}{|Q|}\int_{Q}|b(x)-b_{Q}|{\rm d}x<\infty\bigg\},

其中b_{Q}=\frac{1}{|Q|}\int_{Q}f(y){\rm d}y.

\dot{\Lambda}_{\beta}({\Bbb R}^n)=\bigg\{f\in L^{1}_{{\rm loc}}({\Bbb R}^n):\|f\|_{\dot{\Lambda}_{\beta}({\Bbb R}^n)}:=\sup\limits_{x, y\in{\Bbb R}^n, x\neq y}\frac{|f(x)-f(y)|}{|x-y|^{\beta}}<\infty\bigg\}.

给定f\in L^{1}_{{\rm loc}}({\Bbb R}^n), Hardy-Littlewood极大算子定义为

Mf(x)=\sup\limits_{Q\ni x}\frac{1}{|Q|}\int_{Q}|f(y)|{\rm d}y,

这里上确界取遍所有边平行于坐标轴的方体Q\subset{\Bbb R}^n, |Q|表示Q的Lebesgue测度.

给定\lambda\in(0, 1){\Bbb R}^n上可测函数f,局部Sharp极大算子M_{\lambda}^{\sharp}定义为

M_{\lambda}^{\sharp}f(x)=\sup\limits_{Q\ni x}\inf\limits_{c\in{\Bbb R}}((f-c)\chi_{Q})^{\ast}(\lambda|Q|).

本文主要结果如下

定理1.4 设变量核Marcinkiewicz积分\mu_{\Omega}由(1.3)式所定义, \Omega(x, z)满足条件(1.1), (1.2)和(1.5),且q(\cdot)\in {\cal B}({\Bbb R}^n),则\mu_{\Omega}在变指标Morrey空间上是有界的,即存在与f无关的常数C>0,使得对任意的f\in{\cal M}_{q(\cdot), \mu},有

\|\mu_{\Omega}(f)\|_{{\cal M}_{q(\cdot), \mu}}\leq C\|f\|_{{\cal M}_{q(\cdot), \mu}}.

定理1.5 设b\in {\rm BMO}({\Bbb R}^n), \Omega(x, z)满足条件(1.1), (1.2)和(1.5), q(\cdot)\in {\cal B}({\Bbb R}^n),且函数u满足

\mathop \sum \limits_{j = 1}^\infty (j+1)\frac{\|\chi_{B(x, r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}}{\|\chi_{B(x, 2^{j+1}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}}\frac{u(x, 2^{j+1}r)}{u(x, r)}<C.
(1.7)

\mu_{\Omega}在变指标Morrey空间上是有界的,即存在与f无关的常数C>0,使得对任意的f\in{\cal M}_{q(\cdot), \mu},有

\|\mu_{\Omega}(f)\|_{{\cal M}_{q(\cdot), \mu}}\leq C\|f\|_{{\cal M}_{q(\cdot), \mu}}.

2 定理的证明

证明定理,需要以下引理

引理2.1[13] (广义Hölder不等式) 设q(\cdot)\in{\cal B}({\Bbb R}^n)f\in L^{q(\cdot)}({\Bbb R}^n), g\in L^{q'(\cdot)}({\Bbb R}^n),则f, g{\Bbb R}^n上可积,且有

\int_{{\Bbb R}^{n}}|f(x)g(y)|{\rm d}x \leq r_{q}\|f\|_{L^{q(\cdot)}({\Bbb R}^n)}\|g\|_{L^{q'(\cdot)}({\Bbb R}^n)},

其中r_{q}=1+\frac{1}{q_{-}}-\frac{1}{q_{+}}.

引理2.2[14] 设q(\cdot)\in {\cal B}({\Bbb R}^n),则存在常数C>0,使得对{\Bbb R}^n中所有的球B,有

C^{-1}\leq\frac{1}{|B|}\|\chi_{B}\|_{L^{q(\cdot)}({\Bbb R}^n)}\|\chi_{B}\|_{L^{q'(\cdot)}({\Bbb R}^n)}\leq C .
(2.1)

引理2.3[15] 设g\in L^{1}_{{\rm loc}}({\Bbb R}^n),可测函数\varphi满足对任意\alpha>0

|\{x:|\varphi(x)|>\alpha\}|<\infty,

\int_{{\Bbb R}^{n}}|\varphi(x)g(x)|{\rm d}x \leq C_n\int_{{\Bbb R}^{n}}M^{\sharp}_{\lambda_n}\varphi(x)g(x),
(2.2)

其中\lambda_n\in(0, 1).

引理2.4 若\Omega(x, z)满足条件(1.1), (1.2)和(1.5).假设q(\cdot)\in{\cal B}({\Bbb R}^n),则存在常数C,使得对任意的f\in L^{q(\cdot)}({\Bbb R}^n),有

\|\mu_{\Omega}(f)\|_{L^{q(\cdot)}({\Bbb R}^n)}\leq C_p\|f\|_{L^{q(\cdot)}({\Bbb R}^n)}.

 令f\in L^{\infty}_{c}.对于任意g\in L^{q'(\cdot)}({\Bbb R}^n)\subset L^{1}_{{\rm loc}}({\Bbb R}^n), 由引理2.3,我们有

\begin{eqnarray*} \int_{{\Bbb R}^{n}}|\mu_{\Omega}(f)(x)g(x)|{\rm d}x &\leq&c_n\int_{{\Bbb R}^{n}}M^{\sharp}_{\lambda_n}(\mu_{\Omega}(f))(x)Mg(x){\rm d}x\\ &\leq &c_n\int_{{\Bbb R}^{n}}(1/\lambda_n)^{1/\delta}(\mu_{\Omega}(f))^{\sharp}_{\delta}(x)Mg(x){\rm d}x\\ &\leq &c_n\int_{{\Bbb R}^{n}}Mf(x)Mg(x){\rm d}x\\ &\leq &c_nr_{p}\|Mf\|_{L^{q(\cdot)}({\Bbb R}^n)}\|Mg\|_{L^{q'(\cdot)}({\Bbb R}^n)}\\ &\leq &C_{p}\|f\|_{L^{q(\cdot)}({\Bbb R}^n)}\|g\|_{L^{q'(\cdot)}({\Bbb R}^n)}, \end{eqnarray*}

其中C_{p}=c_nr_{p}\|M\|_{L^{q(\cdot)}({\Bbb R}^n)\rightarrow L^{q(\cdot)}({\Bbb R}^n)}\|M\|_{L^{q'(\cdot)}({\Bbb R}^n)\rightarrow L^{q'(\cdot)}({\Bbb R}^n)}.从而

\|\mu_{\Omega}(f)\|_{L^{q(\cdot)}({\Bbb R}^n)}\leq C_{p}\|f\|_{L^{q(\cdot)}({\Bbb R}^n)}.

由Hardy-Littlewood极大算子M(f)与局部Sharp极大算子M^{\sharp}_{\lambda}(f)的性质,引理2.4得证.

引理2.5[14] 设b\in {\rm BMO}, m\in{\Bbb N}, i, j\in{\Bbb Z},满足i<j, 则有

C^{-1}\|b\|^{m}_{{\rm BMO}({\Bbb R}^n)}\leq\sup\limits_{B}\frac{\|(b-b_{B})^{m}\chi_{B}\|_{L^{q(\cdot)}({\Bbb R}^n)}}{\|\chi_{B}\|_{L^{q(\cdot)}({\Bbb R}^n)}}\leq\|b\|^{m}_{{\rm BMO}({\Bbb R}^n)},
(2.3)

\|(b-b_{B_i})^{m}\chi_{B_j}\|_{L^{q(\cdot)}({\Bbb R}^n)}\leq C(j-i)^{m}\|b\|^{m}_{{\rm BMO}({\Bbb R}^n)}\|\chi_{B}\|_{L^{q(\cdot)}({\Bbb R}^n)},
(2.4)

其中B=(x, r), B_i=(x, 2^{ir}).

引理2.6 若\Omega(x, z)满足条件(1.1), (1.2)和(1.5).假设q(\cdot)\in {\cal B}({\Bbb R}^n),则存在常数C,使得对任意的f\in L^{q(\cdot)}({\Bbb R}^n),有

\|\mu^{b}_{\Omega}(f)\|_{L^{q(\cdot)}({\Bbb R}^n)}\leq C\|b\|_{{\rm BMO}({\Bbb R}^n)}\|f\|_{L^{q(\cdot)}({\Bbb R}^n)}.

利用文献[8]与[16]中相应定理的证明方法可证引理2.6.

定理1.4的证明 设f\in{\cal M}_{q(\cdot), u}.对任意的z\in{\Bbb R}^nr>0,分解f(x)=f_{1}(x)+f_{2}(x),其中f_{1}=f\chi_{B(z, 2r)}, f_{2}=\sum\limits_{j=1}^{\infty}f_{j}, f_{j}=f\chi_{B(z, 2^{j+1}r)\setminus B(z, 2^{j}r)},

\begin{eqnarray*} \frac{1}{u(z, r)}\|\chi_{B(z, r)}\mu_\Omega(f)\|_{L^{q(\cdot)}({\Bbb R}^n)} &\leq&\frac{1}{u(z, r)}\|\chi_{B(z, r)}\mu_\Omega(f_1)\|_{L^{q(\cdot)}({\Bbb R}^n)}\\ &&+\frac{1}{u(z, r)}\|\chi_{B(z, r)}\mu_\Omega(f_2)\|_{L^{q(\cdot)}({\Bbb R}^n)}\\ &=:&E_1+E_2. \end{eqnarray*}

先估计E_1.由引理2.4, \mu_{\Omega}(f)L^{q(\cdot)}({\Bbb R}^n)上有界,所以我们有

\begin{eqnarray*} E_1 &\leq&C\frac{1}{u(z, 2r)}\|\chi_{B(z, 2r)}f\|_{L^{q(\cdot)}({\Bbb R}^n)}\\ &\leq&C\sup\limits_{y\in{\Bbb R}^n, r>0}\frac{1}{u(y, r)}\|\chi_{B(y, r)}f\|_{L^{q(\cdot)}({\Bbb R}^n)}\\ &\leq&C\|f\|_{{\cal M}_{q(\cdot), u}}. \end{eqnarray*}

下面估计E_2.注意到当x\in B(z, r), y\in B(z, 2^{j+1}r)\setminus B(z, 2^{j}r)时,有

2^{j-1}r\leq|y-z|-|x-z|\leq|x-y|<t.

因此,应用Hölder不等式有

\begin{eqnarray*} |\mu_\Omega(f_2)(x)| &\leq&\sum\limits_{j=1}^{\infty}\bigg(\int_{B(z, 2^{j+1}r)\setminus B(z, 2^{j}r)}\frac{\Omega(x, x-y)}{|x-y|^{n-1}}|f(y)|{\rm d}y\bigg)\bigg(\int^{\infty}_{2^{(j-1)n}r^{n}}\frac{{\rm d}t}{t^{3}}\bigg)^{1/2}\\ &\leq&C\sum\limits_{j=1}^{\infty}\frac{1}{|2^{(j+1)n}r^{n}|^{\frac{1}{n}}}\int_{B(z, 2^{j+1}r)\setminus B(z, 2^{j}r)}\frac{\Omega(x, x-y)}{|x-y|^{n-1}}|f(y)|{\rm d}y. \end{eqnarray*}

又由条件(1.5)知\Omega有界,利用引理2.1,有

\begin{eqnarray*} |\mu_\Omega(f_2)(x)|&\leq&C\sum\limits_{j=1}^{\infty}\frac{1}{|2^{(j+1)n}r^{n}|^{\frac{1}{n}}}\int_{B(z, 2^{j+1}r)\setminus B(z, 2^{j}r)}\frac{|f(y)|}{|x-y|^{n-1}}{\rm d}y\\ &\leq&C\sum\limits_{j=1}^{\infty}\frac{1}{|2^{(j+1)n}r^{n}|^{\frac{1}{n}}}\frac{1}{|2^{(j+1)n}r^{n}|^{\frac{n-1}{n}}}\int_{B(z, 2^{j+1}r)}|f(y)|{\rm d}y\\ &\leq&C\sum\limits_{j=1}^{\infty}\frac{1}{2^{(j+1)n}r^{n}}\int_{B(z, 2^{j+1}r)}|f(y)|{\rm d}y\\ &\leq&C\sum\limits_{j=1}^{\infty}\frac{1}{2^{(j+1)n}r^{n}}\|f\chi_{B(z, 2^{j+1}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\|\chi_{B(z, 2^{j+1}r)}\|_{L^{q'(\cdot)}({\Bbb R}^n)}.\end{eqnarray*}

因此

|\chi_{B(z, r)}\mu_\Omega(f_2)(x)|\leq C\mathop \sum \limits_{j = 1}^\infty \frac{1}{2^{(j+1)n}r^{n}}\|f\chi_{B(z, 2^{j+1}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\|\chi_{B(z, 2^{j+1}r)}\|_{L^{q'(\cdot)}({\Bbb R}^n)}\cdot\chi_{B(z, r)}.

上式两端同时取范数\|\cdot\|_{L^{q(\cdot)}({\Bbb R}^n)},可得

\begin{eqnarray*} \|\chi_{B(z, r)}\mu_\Omega(f_2)(x)\|_{L^{q(\cdot)}({\Bbb R}^n)} &\leq&C\sum\limits_{j=1}^{\infty}\frac{1}{2^{(j+1)n}r^{n}}\|f\chi_{B(z, 2^{j+1}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\|\chi_{B(z, 2^{j+1}r)}\|_{L^{q'(\cdot)}({\Bbb R}^n)}\\ &&\cdot\|\chi_{B(z, r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}. \end{eqnarray*}

在引理2.2中,取B=B(z, 2^{j+1}r),则

\|\chi_{B(z, 2^{j+1}r)}\|_{L^{q'(\cdot)}({\Bbb R}^n)}\leq C\frac{2^{(j+1)n}r^{n}}{\|\chi_{B(z, 2^{j+1}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}}.
(2.5)

由(2.5)式知

\begin{eqnarray*} &&\|\chi_{B(z, r)}\mu_\Omega(f_2)(x)\|_{L^{q(\cdot)}({\Bbb R}^n)} \\&\leq&C\sum\limits_{j=1}^{\infty}\frac{1}{2^{(j+1)n}r^{n}}\|f\chi_{B(z, 2^{j+1}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\frac{2^{(j+1)n}r^{n}}{\|\chi_{B(z, 2^{j+1}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}}\|\chi_{B(z, r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\\ &\leq&C\sum\limits_{j=1}^{\infty}\frac{\|\chi_{B(z, r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}}{\|\chi_{B(z, 2^{j+1}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}}\frac{u(z, 2^{(j+1)}r)}{u(z, 2^{(j+1)}r)}\|f\chi_{B(z, 2^{j+1}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\\ &\leq&C\sum\limits_{j=1}^{\infty}\frac{\|\chi_{B(z, r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}u(z, 2^{(j+1)}r)}{\|\chi_{B(z, 2^{j+1}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}}\sup\limits_{z\in{\Bbb R}^n, r>0}\frac{1}{u(z, r)}\|\chi_{B(z, r)}f\|_{L^{q(\cdot)}({\Bbb R}^n)}. \end{eqnarray*}

由定义1.2,若u\in{\Bbb W}_{q(\cdot)},有

\mathop \sum \limits_{j = 1}^\infty \frac{\|\chi_{B(z, r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}}{\|\chi_{B(z, 2^{j+1}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}}\frac{u(z, 2^{(j+1)}r)}{u(z, r)}<C.

因此

E_2\leq C\|f\|_{{\cal M}_{q(\cdot), u}}.

从而定理1.4得证.

定理1.5的证明 设f\in{\cal M}_{q(\cdot), u}, b\in {\rm BMO}({\Bbb R}^n)对任意的z\in{\Bbb R}^nr>0,分解f(x)=f_{1}(x)+f_{2}(x),其中f_{1}=f\chi_{B(z, 2r)}, f_{2}=\sum\limits_{j=1}^{\infty}f_{j}, f_{j}=f\chi_{B(z, 2^{j+1}r)\setminus B(z, 2^{j}r)},

\begin{eqnarray*} &&\frac{1}{u(z, r)}\|\chi_{B(z, r)}\mu_{\Omega}^{b}(f)\|_{L^{q(\cdot)}({\Bbb R}^n)}\\ &\leq&\frac{1}{u(z, r)}\|\chi_{B(z, r)}\mu_{\Omega}^{b}(f_1)\|_{L^{q(\cdot)}({\Bbb R}^n)}+\frac{1}{u(z, r)}\|\chi_{B(z, r)}\mu_{\Omega}^{b}(f_2)\|_{L^{q(\cdot)}({\Bbb R}^n)}\\ &=:&F_1+F_2. \end{eqnarray*}

由引理2.6及定理1.4中关于E_1的估计,我们有F_1\leq C\|f\|_{{\cal M}_{q(\cdot), u}}.

以下估计F_2, x\in B(z, r), y\in B(z, 2^{j+1}r)\setminus B(z, 2^{j}r)时,有

2^{j-1}r\leq|y-z|-|x-z|\leq|x-y|<t.

因此,应用Hölder不等式有

\begin{array}{l} \|\mu_\Omega^{b}(f)(x)\| =\bigg(\int^{\infty}_{0}\bigg|\int_{(B(z,r))^{c}\bigcap\{y:|x-y|<t\}}\frac{\Omega(x,x-y)}{|x-y|^{n-1}}[b(x)-b(y)]f(y)\bigg|^{2}\frac{{\rm d}t}{t^{3}}\bigg)^{\frac{1}{2}}\\ \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\leq\sum\limits_{j=1}^{\infty}\bigg(\int_{B(z,2^{j+1}r)\setminus B(z,2^{j}r)}\frac{\Omega(x,x-y)}{|x-y|^{n-1}}[b(x)-b(y)]|f(y)|{\rm d}y\bigg)\bigg(\int^{\infty}_{2^{(j-1)n}r^{n}}\frac{{\rm d}t}{t^{3}}\bigg)^{\frac{1}{2}}\\ \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\leq C\sum\limits_{j=1}^{\infty}\frac{1}{|2^{(j+1)n}r^{n}|^{\frac{1}{n}}}\cdot\int_{B(z,2^{j+1}r)\setminus B(z,2^{j}r)}\frac{\Omega(x,x-y)}{|x-y|^{n-1}}[b(x)-b(y)]|f(y)|{\rm d}y. \end{array}

应用广义Hölder不等式,有

\begin{eqnarray*} \|\mu_\Omega^{b}(f)(x)\| &\leq&C\sum\limits_{j=1}^{\infty}\frac{1}{|2^{(j+1)}r|^{\frac{1}{n}}}\cdot\int_{B(z, 2^{j+1}r)\setminus B(z, 2^{j}r)}\frac{|b(x)-b(y)|}{|x-y|^{n-1}}|f(y)|{\rm d}y\\ &\leq&C\sum\limits_{j=1}^{\infty}\frac{1}{|2^{(j+1)n}r^{n}|^{\frac{1}{n}}}\frac{1}{|2^{(j+1)}r|^{\frac{n-1}{n}}}\int_{B(z, 2^{j+1}r)}|b(x)-b(y)||f(y)|{\rm d}y\\ &\leq&C\sum\limits_{j=1}^{\infty}\frac{1}{2^{(j+1)n}r^{n}}\int_{B(z, 2^{j+1}r)}|b(x)-b(y)||f(y)|{\rm d}y\\ &\leq&C\sum\limits_{j=1}^{\infty}\frac{1}{2^{(j+1)n}r^{n}}|b(x)-b_{B(z, r)}|\int_{B(z, 2^{j+1}r)}|f(y)|{\rm d}y\\ &&+ C\sum\limits_{j=1}^{\infty}\frac{1}{2^{(j+1)n}r^{n}}\int_{B(z, 2^{j+1}r)}|b_{B(z, r)}-b(y)||f(y)|{\rm d}y\\ &\leq&C\sum\limits_{j=1}^{\infty}\frac{1}{2^{(j+1)n}r^{n}}|b(x)-b_{B(z, r)}|\|f\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\|\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q'(\cdot)}({\Bbb R}^n)}\\ &&+C\sum\limits_{j=1}^{\infty}\frac{1}{2^{(j+1)n}r^{n}}\|f\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\|(b_{B(z, r)}-b)\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q'(\cdot)}({\Bbb R}^n)}, \end{eqnarray*}

现记I=\|\chi_{B(z, r)}\mu_{\Omega}^{b}(f_2)\|_{L^{q(\cdot)}({\Bbb R}^n)},则

\begin{eqnarray*} I &\leq&C\sum\limits_{j=1}^{\infty}\frac{1}{2^{(j+1)n}r^{n}}\|f\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\|\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q'(\cdot)}({\Bbb R}^n)}\\ &&\cdot\|(b-b_{B(z, r)})\chi_{B(z, r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\\ &&+C\sum\limits_{j=1}^{\infty}\frac{1}{2^{(j+1)n}r^{n}}\|f\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\|(b_{B(z, r)}-b)\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q'(\cdot)}({\Bbb R}^n)}\\ &&\cdot\|\chi_{B(z, r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}. \end{eqnarray*}

由引理2.5,有

\begin{eqnarray*} I &\leq&C\sum\limits_{j=1}^{\infty}\frac{1}{2^{(j+1)n}r^{n}}\|f\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\|\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q'(\cdot)}({\Bbb R}^n)}\|b\|_{{\rm BMO}} \|\chi_{B(z, r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\\ &&+C\sum\limits_{j=1}^{\infty}\frac{j+1}{2^{(j+1)n}r^{n}}\|f\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\|\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q'(\cdot)}({\Bbb R}^n)}\|b\|_{{\rm BMO}} \|\chi_{B(z, r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\\ &\leq&C\sum\limits_{j=1}^{\infty}\frac{j+1}{2^{(j+1)n}r^{n}}\|b\|_{{\rm BMO}}\|f\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\|\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q'(\cdot)}({\Bbb R}^n)} \|\chi_{B(z, r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}. \end{eqnarray*}

将(2.5)式代入上式,可得

\begin{eqnarray*} I &\leq&C\sum\limits_{j=1}^{\infty}\frac{j+1}{2^{(j+1)n}r^{n}}\|b\|_{{\rm BMO}({\Bbb R}^n)}\|f\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\\ &&\cdot\|b\|_{{\rm BMO}({\Bbb R}^n)} \frac{2^{(j+1)n}r^{n}}{\|\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}} \|\chi_{B(z, r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\\ &\leq&C\sum\limits_{j=1}^{\infty}(j+1)\|b\|_{{\rm BMO}({\Bbb R}^n)}\frac{\|\chi_{B(z, r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}}{\|\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q(\cdot)} ({\Bbb R}^n)}}\frac{u(z, 2^{(j+1)}r)}{u(z, 2^{(j+1)}r)}\|f\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}\\ &\leq&C\sum\limits_{j=1}^{\infty}(j+1)\|b\|_{{\rm BMO}({\Bbb R}^n)}\frac{\|\chi_{B(z, r)}\|_{L^{q(\cdot)}({\Bbb R}^n)}u(z, 2^{(j+1)}r)}{\|\chi_{B(z, 2^{(j+1)}r)}\|_{L^{q(\cdot)} ({\Bbb R}^n)}}\\ &&\cdot\sup\limits_{y\in{\Bbb R}^n, r>0}\frac{1}{u(y, r)}\|\chi_{B(y, r)}f\|_{L^{q(\cdot)}({\Bbb R}^n)}. \end{eqnarray*}

因此,由(1.7)式,可得

F_2\leq C\|b\|_{{\rm BMO}({\Bbb R}^n)}\|f\|_{{\cal M}_{q(\cdot), u}}.

至此,定理1.5得证.

参考文献

Stein E M .

On the function of Littlewood-Paley, Lusin and Marcinkiewicz

Trans Amer Math Soc, 1958, 88: 430- 466

DOI:10.1090/S0002-9947-1958-0112932-2      [本文引用: 1]

Calderón A P , Zygmund A .

On a problem of Mihlin

Trans Amer Math Soc, 1995, 78: 209- 224

URL     [本文引用: 1]

Ding Y , Lin Q C , Shao S L .

On the Marcinkiewicz integral with variable kernels

Indiana Univ Math J, 2004, 53 (3): 805- 821

DOI:10.1512/iumj.2004.53.2406      [本文引用: 1]

陶双平, 邵旭馗.

带变量核的Marcinkiewicz积分算子在齐次Morrey-Herz空间的有界性

兰州大学学报(自然科学版), 2010, 46 (3): 102- 107

DOI:10.3969/j.issn.1000-2804.2010.03.015      [本文引用: 1]

Tao S P , Shao X K .

Boundedness of Marcinkiewicz integrals with variable kernel on the homogeneous Morrey-Herz spaces

Journal of Lanzhou University (Natural Science), 2010, 46 (3): 102- 107

DOI:10.3969/j.issn.1000-2804.2010.03.015      [本文引用: 1]

邵旭馗, 陶双平.

带变量核的Marcinkiewicz积分交换子的加权Lipschitz估计

系统科学与数学, 2012, 32 (7): 915- 921

URL     [本文引用: 1]

Shao X K , Tao S P .

Weighted Lipschitz estimates for commutators of Marcinkiewicz integrals with variable kernel

J Sys Sci and Math Scis, 2012, 37 (2): 915- 921

URL     [本文引用: 1]

闫彦宗, 邵旭馗, 王素萍.

变量核的Marcinkiewicz高阶交换子在Hardy空间的有界性

山东大学学报(理学版), 2013, 48 (2): 67- 71

URL     [本文引用: 1]

Yan Y Z , Shao X K , Wang S P .

Boundedness of Marcinkiewicz integral higher commutators with variable kernels on Hardy spaces

Journal of Shandong University (Science Edition), 2013, 48 (2): 67- 71

URL     [本文引用: 1]

Cruz-Uribe D , Fiorenza A , Martell J , Pérez C .

The boundedness of classical operators on variable Lp spaces

Ann Acad Sci Fenn Math, 2006, 31 (2): 239- 264

URL     [本文引用: 2]

王洪彬, 傅尊伟, 刘宗光.

变指标Lebesgue空间上的Marcinkiewicz积分高阶交换子

数学物理学报, 2012, 32A (6): 1092- 1101

DOI:10.3969/j.issn.1003-3998.2012.06.009      [本文引用: 2]

Wang H B , Fu Z W , Liu Z G .

Higher-order commutators of Marcinkiewicz integrals on variable Lebesgue spaces

Acta Mathematica Scientia, 2012, 32A (6): 1092- 1101

DOI:10.3969/j.issn.1003-3998.2012.06.009      [本文引用: 2]

Liu Z G , Wang H B .

Boundedness of Marcinkiewicz integral on Herz spaces with variable exponent

Jordan J Math Stat, 2012, 5 (4): 223- 239

URL     [本文引用: 1]

陶双平, 李露露.

变指标Morrey空间上的Marcinkiewicz积分

数学年刊, 2016, 37A (1): 55- 70

URL     [本文引用: 1]

Tao S P , Li L L .

Boundedness of Marcinkiewicz integrals and commutators on Morrey spaces with variable exponents

Chinese Annals of Mathematics, 2016, 37A (1): 55- 70

URL     [本文引用: 1]

Wang W , Xu J S .

Multilinear Calderón-Zygmund operators and their commutators with BMO functions in variable exponent Morrey spaces

Frontiers of Mathematics in China, 2017, 12 (5): 1235- 1246

DOI:10.1007/s11464-017-0653-0      [本文引用: 1]

Ho K P .

The fractional integral operators on Morrey spaces with variable exponent on unbounded domains

Math Inequal Appl, 2013, 16 (3): 363- 373

URL     [本文引用: 2]

Kováčik O , Rákosník J .

On spaces Lp(x) and Wk, p(x)

Czechoslovak Math J, 1991, 41 (4): 592- 618

URL     [本文引用: 1]

Izuki M .

Fractional integrals on Herz-Morrey spaces with variable exponent

Hiroshima Math J, 2010, 40 (3): 343- 355

DOI:10.32917/hmj/1291818849      [本文引用: 2]

Lerner A K .

Weighted norm inequality for the local sharp maximal function

J Fourier Anal Appl, 2004, 10: 465- 474

URL     [本文引用: 1]

王素萍, 陶双平, 邵旭馗.

变量核Marcinkiewicz积分交换子在齐次Morrey-Herz空间中的有界性

系统科学与数学, 2013, 33 (12): 1498- 1506

URL     [本文引用: 1]

Wang S P , Tao S P , Shao X K .

Boundedness of Marcinkiewicz integral commutators with variable kernels on homogeneous Morrey-Herz spaces

J Sys Sci and Math Scis, 2013, 33 (12): 1498- 1506

URL     [本文引用: 1]

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