Abstract
In this paper, we first give some new characterizations of Muckenhoupt type weights through establishing the boundedness of maximal operators on the weighted Lorentz and Morrey spaces. Secondly, we establish the boundedness of sublinear operators including many interesting in harmonic analysis and its commutators on the weighted Morrey spaces. Finally, as an application, the boundedness of strongly singular integral operators and commutators with symbols in BMO space are also given.
Similar content being viewed by others
Avoid common mistakes on your manuscript.
1 Introduction
Let f be a locally integrable function on \({\mathbb {R}}^n\). The Hardy–Littlewood maximal operator of f is defined by
where the supremum is taken over all cubes containing x. It is well known that the Hardy–Littlewood maximal operator is one of the most important operators and plays a key role in harmonic analysis since maximal operators could control crucial quantitative information concerning the given functions. It is very a powerful tool for solving crucial problems in analysis, for example, applications to differentiation theory, in the theory of singular integral operators and partial differential equations (see [2, 14, 25, 38, 45, 46, 48] for more details).
It is very important to study weighted estimates for maximal operators in harmonic analysis. Muckenhoupt [33] first discovered the weighted norm inequality for the Hardy–Littlewood maximal operators in the real setting. More precisely, it is proved that for \(1<p<\infty \),
holds for all f in the weighted Lebesgue space \(L^p(\omega (x)dx)\) if and only if \(\omega \) belongs to the class of Muckenhoupt weights denoted by \(A_p\).
Later, Coifman and Fefferman [10] extended the theory of Muckenhoupt weights to general Calderón–Zygmund operators. They also proved that \(A_p\) weights satisfy the crucial reverse Hölder condition. For further readings on the reverse Hölder property for Muckenhoupt weights on spaces of homogeneous type, see [22]. The weighted norm inequalities for the maximal operators are also extended to the vector valued setting by Andersen and John in the work [4], and to the Lorentz spaces by Chung et al. in [7]. It is well known that the theory of weighted functions plays an important role in the study of boundary value problems on Lipschitz domains, in theory of extrapolation of operators and applications to certain classes of nonlinear partial differential equation.
It is also useful to remark that in 2012, Tang [49] established the weighted norm inequalities for maximal operators and pseudodifferential operators with smooth symbols associated to the class of new weighted functions \(A_p(\varphi )\) (see in Sect. 2 below for more details) including the Muckenhoupt weighted functions. It should be pointed out that the class of \( A_p(\varphi )\) weights do not satisfy the doubling condition.
It is well known that Morrey [34] introduced the classical Morrey spaces to study the local behavior of solutions to second order elliptic partial differential equations. Moreover, it is found that many properties of solutions to partial differential equations can be attributed to the boundedness of some operators on Morrey spaces. Also, the Morrey spaces have many important applications to Navier–Stokes and Schrödinger equations, elliptic equations with discontinuous coefficients and potential theory (see, for example, [1, 6, 13, 31, 36, 40, 43, 50] and therein references). During last decades, the theory of Morrey spaces has been significantly developed into different contexts, including the study of classical operators of harmonic analysis, for instance, maximal functions, potential operators, singular integrals, pseudodifferential operators, Hausdorff operators and their commutators in generalizations of these spaces (see [3, 8, 12, 17, 18, 26, 30, 32, 36, 37, 42]). In the recent years, there is an increasing interest on the study of the problems concerning the two-weight norm inequality for maximal operators on the Morrey spaces. More details, for example, one may find in [20, 47] and the references therein. Especially, Wang et al. [51] recently have established the interesting connection between the \(A_p\) weights and Morrey spaces. More precisely, some new characterizations of Muckenhoupt weights are given by replacing the Lebesgue spaces by the Morrey spaces. Motivated by all of the above mentioned facts, the first main result of this paper is to give some new characterizations of Muckenhoupt type weights such as \(A_p\), A(p, 1), and \(A_p(\varphi )\) by establishing the boundedness of maximal operators on the weighted Morrey and Lorentz spaces. In particular, we give the weighted norm inequality of weak type for new dyadic maximal operators associated to the \(A_p^{{\varDelta },\eta }(\varphi )\) dyadic weights. The results are given in Sect. 3 of the paper.
The second main result of this paper is to study the boundedness of sublinear operators including many interesting operators in harmonic analysis, such as the Calderón–Zygmund operator, Hardy–Littlewood maximal operator, strongly singular integrals, and so on, on the weighted Morrey spaces.
Let us first give the definition of sublinear operators with strongly singular kernels. Let the operator \({\mathcal {T}}\) be well defined on the space of all infinitely differential functions with compact support \(C^\infty _c({\mathbb {R}}^n)\). It is said that \({\mathcal {T}}\) is a strongly singular sublinear operator if it is a linear or sublinear operator and satisfies the size condition as follows
for all \(f\in C^\infty _c({\mathbb {R}}^n)\), where \(\lambda \) is a non-negative real number.
For a measurable function b, the commutator operator \([b, {\mathcal {T}}]\) is defined as a linear or a sublinear operator such that
for every \(f\in C^\infty _c({\mathbb {R}}^n)\). For \(\lambda \le 0\), the sublinear operators \({\mathcal {T}}\) and \([b, {\mathcal {T}}]\) have been investigated by many authors. For example, see in the works [17, 27, 44] and therein references. In the Sect. 4 of the paper, we establish the boundedness of sublinear operators \({\mathcal {T}}\) and \([b, {\mathcal {T}}]\) for \(\lambda \ge 0\) on the weighted Morrey type spaces. As an application, we obtain some new results about boundedness of strongly singular integral operators and their commutators with symbols in BMO space on the weighted Morrey spaces. Moreover, maximal singular integral operators of Andersen and John type are studied on the two weighted Morrey spaces with vector valued functions in Sect. 4.
2 Some notations and definitions
Throught the whole paper, we denote by C a positive geometric constant that is independent of the main parameters, but can change from line to line. We also write \(a\lesssim b\) to mean that there is a positive constant C, independent of the main parameters, such that \(a \le Cb\). The symbol \(f\simeq g\) means that f is equivalent to g (i.e. \(C^{-1} f\le g \le Cf)\). As usual, \(\omega (\cdot )\) is a non-negative weighted function on \({\mathbb {R}}^n\). Denote \(\omega (B)^{\alpha }=\big (\int _B\omega (x)dx\big )^{\alpha }\), for \(\alpha \in {\mathbb {R}}\). Remark that if \(\omega (x) = x^{\beta }\) for \(\beta > -n\), then we have
We also denote by \(B_r(x_0)=\{x\in {\mathbb {R}}^n:|x-x_0|<r\}\) a ball of radius r with center at \(x_0\), and let rB define the ball with the same center as B whose radius is r times radius of B.
Now, we are in a position to give some notations and definitions of weighted Morrey spaces.
Definition 1
Let \(1 \le q< \infty , 0< \kappa < 1\) and \(\omega _1\) and \(\omega _2\) be two weighted functions. Then two weighted Morrey space is defined by
where
It is easy to see that \({\mathcal {M}}^{q,\kappa }_{\omega _1,\omega _2}({\mathbb {R}}^n)\) is a Banach space. Note that if \(\omega _1=\omega , \omega _2=1\), we then write \({\mathcal {M}}^{q,\kappa }(\omega ,{\mathbb {R}}^n):={\mathcal {M}}^{q,\kappa }_{\omega _1,\omega _2}({\mathbb {R}}^n)\). Also, if \(\omega _1=\omega _2=\omega \), then we denote \({\mathcal {M}}^{q,\kappa } _\omega ({\mathbb {R}}^n):= {{\mathcal {M}}}^{q,\kappa }_{\omega _1,\omega _2}({\mathbb {R}}^n)\). In particular, for \(\omega =1\) we write \({\mathcal {M}}^{q,\kappa } ({\mathbb {R}}^n):={\mathcal {M}}^{q,\kappa }_\omega ({\mathbb {R}}^n)\).
Definition 2
Let \(1 \le q< \infty , 0< \kappa < 1\). The weighted local Morrey space is defined by
where
Note that for \(1\le q\le p<\infty \), the local Morrey space \({\mathcal {M}}^{q,1-\frac{q}{p}}_{{\mathrm{loc}}}({\mathbb {R}}^n)\) has some important applications to the Navier–Stokes equations and other evolution equations (see in [16, 50] for more details).
Definition 3
Let \(1 \le q < \infty \) and \(0< \kappa < 1\). The weighted inhomogeneous Morrey space is defined by
where
If \(\omega =1\) and \(1\le q\le p<\infty \), then the inhomogeneous Morrey space \({M}^{q,1-\frac{q}{p}}_\omega ({\mathbb {R}}^n)\) is introduced by Alvarez, Guzmán–Partida and Lakey (see in [3] for more details). Note that \({\mathcal {M}}^{q,\kappa }_{{\mathrm{loc}}}({\mathbb {R}}^n)\) and \({M}^{q,\kappa }_\omega ({\mathbb {R}}^n)\) are two Banach spaces.
Definition 4
Let \(1 \le q< \infty , 0< \kappa < 1\) and \(\omega \) be a weighted function. The weighted Morrey space is defined by
where
From this, for convenience, we denote \(M^p_{q,\omega }({\mathbb {R}}^n):={\mathcal {L}}^{q,1-\frac{q}{p}}_{\omega }({\mathbb {R}}^n)\) for the case \(0< q< p < \infty \).
Definition 5
Let \(0< q \le p < \infty \) and \(\omega \) be a weighted function. Then the weighted weak Morrey space is defined by
where
For a measurable function f on \({\mathbb {R}}^n\), the distribution function of f associated with the measure \(\omega (x)dx\) is defined as follows
The decreasing rearrangement of f with respect to the measure \(\omega (x)dx\) is the function \(f^*\) defined on \([0, \infty )\) as follows
Definition 6
(Sect. 2 in [7]) Let \(0 < p, q \le \infty \). The weighted Lorentz space \(L^{p,q}_\omega ({\mathbb {R}}^n)\) is defined as the set of all measurable functions f such that \(\Vert f\Vert _{L^{p,q}_\omega ({\mathbb {R}}^n)}<\infty \), where
Remark that if either \(1< p < \infty \) and \(1 \le q \le \infty \), or \(p = q = 1\), or \(p = q = \infty \) then \(L^{p,q}_\omega ({\mathbb {R}}^n)\) is a quasi-Banach space (see [7, 28]). Moreover, there is constant \(C > 0\) such that
Corollary 1
(page 253 in [21] and Corollary 2.3 in [51]) If \(0< r< q< p < \infty \), \(1\le q_1\le q_2\le \infty \) and \(\omega \) is a non-negative weighted function on \({\mathbb {R}}^n\), then there exists a constant \(C > 0\) such that
Next, we present some basic facts on the class of weighted functions A(p, 1) with \(1< p < \infty \). For further information on the weights, the interested readers may refer to the work [7]. The weighted function \(\omega (x)\) is in A(p, 1) if there exists a positive constant C such that for any cube Q, we have
Lemma 1
(Lemma 2.8 in [7]) For \(1\le p<\infty \), we have \(\omega \in A(p, 1)\) if and only if there exists a constant C such that for any cube Q and subset \(E \subset Q\),
Remark that if \(\omega \in A(p,1)\) with \(1\le p<\infty \) and \(0<\kappa <1\), then \({\mathcal {M}}^{p,\kappa }_\omega ({\mathbb {R}}^n)={\mathcal {L}}^{p,\kappa }_{\omega }({\mathbb {R}}^n)\) with equivalence of norms.
Let \(1 \le r < \infty \) and \(\mathbf {f}=\{f_k\}\) be a sequence of measurable functions on \({\mathbb {R}}^n\). We denote
As usual, the vector-valued space \(X(\ell ^r,{\mathbb {R}}^n)\) is defined as the set of all sequences of measurable functions \(\mathbf {f}=\{f_k\}\) such that
where X is an appropriate Banach space.
Let us recall to define the BMO spaces of John and Nirenberg. For further information on these spaces as well as their deep applications in harmonic analysis, one can see in the famous book of Stein [45].
Definition 7
The bounded mean oscillation space \(BMO({\mathbb {R}}^n)\) is defined as the set of all functions \(b\in L^1_{{\mathrm{loc}}}({\mathbb {R}}^n)\) such that
where \(b_Q=\frac{1}{|Q|}\int _Q b(x)dx\).
Lemma 2
([45]) If \(1<p<\infty \), we then have
Proposition 1
(Proposition 3.2 in [48]) If \(b\in BMO({\mathbb {R}}^n)\), then
Let us recall the definition of \(A_p\) weights. For further readings on \(A_p\) weights, the reader may find in the interesting book [19].
Definition 8
Let \(1< p < \infty \). It is said that a weight \(\omega \in A_p({\mathbb {R}}^n)\) if there exists a constant C such that for all cubes Q,
A weight \(\omega \in A_1({\mathbb {R}}^n)\) if there is a constant C such that
We denote \(A_\infty ({\mathbb {R}}^n)=\mathop \cup \nolimits _{1\le p<\infty }A_p({\mathbb {R}}^n)\).
A closing relation to \(A_\infty ({\mathbb {R}}^n)\) is the reverse Hölder condition. If there exist \(r > 1\) and a fixed constant C such that
for all balls \(B \subset {\mathbb {R}}^n\), we then say that \(\omega \) satisfies the reverse Hölder condition of order r and write \(\omega \in RH_r ({\mathbb {R}}^n)\). According to Theorem 19 and Corollary 21 in [24], \(\omega \in A_\infty ({\mathbb {R}}^n)\) if and only if there exists some \(r > 1\) such that \(\omega \in RH_r ({\mathbb {R}}^n)\). Moreover, if \(\omega \in RH_r ({\mathbb {R}}^n),r>1\), then \(\omega \in RH_{r+\varepsilon } ({\mathbb {R}}^n)\) for some \(\varepsilon >0\). We thus write \(r_\omega = \sup \{r > 1 : \omega \in RH_r ({\mathbb {R}}^n)\}\) to denote the critical index of \(\omega \) for the reverse Hölder condition.
Proposition 2
Let \(\omega \in A_p({\mathbb {R}}^n) \cap RH_r({\mathbb {R}}^n), p \ge 1\) and \(r > 1\). Then, there exist two constants \(C_1, C_2 > 0\) such that
for any ball B and for any measurable subset E of B.
Proposition 3
If \(\omega \in A_p({\mathbb {R}}^n)\), \(1 \le p < \infty \), then for any \(f\in L^1_{{\mathrm{loc}}}({\mathbb {R}}^n)\) and any ball \(B \subset {\mathbb {R}}^n\), we have
Next, we write \(\omega \in {\varDelta }_2\), the class of doubling weights, if there exists \(D > 0\) such that for any cube Q, we have
It is known that if \(\omega \in A_\infty ({\mathbb {R}}^n)\) then \(\omega \in {\varDelta }\). Now, let us recall the class of \( A_p(\varphi )\) weights proposed by Tang in the work [49].
Definition 9
Let \(1< p < \infty \) and \(\varphi (t)=(1+t)^{\alpha _0}\) for \(\alpha _0>0\) and \(t\ge 0\). We say that a weight \(\omega \in A_p(\varphi )\) if there exists a constant C such that for all cubes Q,
A weight \(\omega \in A_1(\varphi )\) if there is a constant C such that
where
Denote \(A_\infty (\varphi )=\mathop \cup \nolimits _{1\le p<\infty } A_p(\varphi )\). It is useful to remark that the \( A_p(\varphi )\) weights do not satisfy the doubling condition. For instance, \(\omega (x)=(1+|x|)^{(-n+\eta )}\) for \(0\le \eta \le n\alpha _0\) is in \(A_1(\varphi )\), but not in \(A_p\) weights and \(\omega (x)dx\) is not a doubling measure. It is also important to see that \(M_\varphi \) may be not bounded on the weighted Lebesgue spaces \(L^p_\omega ({\mathbb {R}}^n)\) for every \(\omega \in A_p(\varphi )\). To be more precise, see in Lemma 2.3 in [49]. Similarly, in this paper we also introduce a class of dyadic weighted functions associated to the function \(\varphi \) as follows.
Definition 10
Let \(1<p<\infty \) and \(0<\eta <\infty \). A weight \(\omega \in A_p^{{\varDelta },\eta }(\varphi )\) if there exists a constant C such that for all dyadic cubes Q,
It is obvious that \(A_{p_1}^{{\varDelta },\eta }(\varphi )\subset A_{p_2}^{{\varDelta },\eta }(\varphi )\) for all \(1<p_1<p_2<\infty \). It is also easy to show that \(A_p({\mathbb {R}}^n)\subset A_p(\varphi )\subset A_p^{{\varDelta },\eta }(\varphi )\) with \(1<p<\infty \) and \(0< \eta <\infty \). In particular, \(A_1({\mathbb {R}}^n) \subset A_1(\varphi )\).
Next, we give the definitions of the maximal operators \(M_\omega \) and \(M^{\varDelta }_{\varphi ,\eta }\) as follows
Remark that by the similar arguments to Lemma 2.1 in [49], we also have
where \(\omega \in A_{p}^{{\varDelta },\eta }(\varphi )\) for \(0<\eta <\infty \) and \(1<p<\infty \). Moreover, we also get the same result as in Lemma 2.3 of the paper [49].
Lemma 3
Let \(1<p<\infty \) and \(\omega \in A_p^{{\varDelta },\eta }(\varphi )\). Then, for any \(p<r<\infty \), we have
It seems to see that the inequality in Lemma 3 may be not valid for \(r=p\).
Theorem 1
(Theorem 3.1 in [4]) If \(1< p < \infty \), then the operator M is bounded from \(L^p_\omega (\ell ^r, {\mathbb {R}}^n)\) to itself if and only if \(\omega \in A_p\).
Theorem 2
(Theorem 2.12 in [9]) If \(1< p< r < \infty \), then the operator M is bounded from \(L^{p,1}_\omega (\ell ^r, {\mathbb {R}}^n)\) to \(L^{p,\infty }_\omega (\ell ^r, {\mathbb {R}}^n)\) if and only if \(\omega \in A(p, 1)\).
Lemma 4
(Lemma 2.3 in [49]) If \(1 \le p < \infty \), then the operator \(M_\varphi \) is bounded from \(L^p_\omega ({\mathbb {R}}^n)\) to \(L^{p,\infty }_\omega ({\mathbb {R}}^n)\) if and only if \(\omega \in A_p(\varphi )\).
In 1981, Andersen and John [4] established the weighted norm inequalities for vector-valued maximal functions and maximal singular integrals on the space \(L^p_\omega (\ell ^r,{\mathbb {R}}^n)\). Now, let us recall the definition of maximal singular integrals associated to the kernels due to Andersen and John. For more details, see in the work [4].
Definition 11
Let K be the kernel such that
where A is a constant and \(\mu \) is non-decreasing on the positive real half-line, \(\mu (2t)\le C\mu (t)\) for all \(t > 0\), and satisfies the Dini condition
Then, the maximal singular integral operator \(T^*\) is defined by
If \(\{K_k (x)\}\) denote a sequence of singular convolution kernels satisfying the above conditions (2.3)–(2.5) with a uniform constant A and a fixed function \(\mu \) not dependent of k, then we write \(T^*(\mathbf {f})=\{T^*_k(f_k) \}\), where \(T^*_k\) is the operator above corresponding to the kernel \(K_k\) .
Theorem 3
(Theorem 5.2 in [4]) Let \(1< r< \infty , 1< p < \infty ,\) and suppose \(\omega \in A_p\). There exits a constant C such that
Let b be a measurable function. We denote by \({\mathcal {M}}_b\) the multiplication operator defined by \({\mathcal {M}}_bf (x)=b(x) f (x)\) for any measurable function f. If \({\mathcal {H}}\) is a linear or sublinear operator on some measurable function space, the commutator of Coifman–Rochberg–Weiss type formed by \({\mathcal {M}}_b\) and \({\mathcal {H}}\) is defined by \([{\mathcal {M}}_b, {\mathcal {H}}]f (x)=({\mathcal {M}}_b{\mathcal {H}}-{\mathcal {H}}{\mathcal {M}}_b) f (x)\).
3 The results about the boundedness of maximal operators
By using Theorem 1 and estimating as Theorem 1.1 in [51], we immediately have the following useful characterization for the Muckenhoupt weights through boundedness of the Hardy–Littlewood maximal operators on the vector valued function spaces.
Theorem 4
Let \(1< q< p< \infty , 1<r <\infty \). Then, the following statements are equivalent:
- 1.
\(\omega \in A_p\);
- 2.
M is a bounded operator from \(L^p_\omega (\ell ^r,{\mathbb {R}}^n)\) to \(L^{p,\infty }_\omega (\ell ^r,{\mathbb {R}}^n)\);
- 3.
M is a bounded operator from \(L^p_\omega (\ell ^r,{\mathbb {R}}^n)\) to \(M^{p}_{q,\omega }(\ell ^r,{\mathbb {R}}^n)\);
- 4.
M is a bounded operator from \(L^p_\omega (\ell ^r,{\mathbb {R}}^n)\) to \(WM^{p}_{q,\omega }(\ell ^r,{\mathbb {R}}^n)\).
Now, we give a new characterization for the class of A(p, 1) weights.
Theorem 5
Let \(1< q< p< r < \infty \). The following statements are equivalent:
- 1.
\(\omega \in A(p,1)\);
- 2.
M is a bounded operator from \(L^{p,1}_\omega (\ell ^r,{\mathbb {R}}^n)\) to \(L^{p,\infty }_\omega (\ell ^r,{\mathbb {R}}^n)\);
- 3.
M is a bounded operator from \(L^{p,1}_\omega (\ell ^r,{\mathbb {R}}^n)\) to \(M^{p}_{q,\omega }(\ell ^r,{\mathbb {R}}^n)\);
- 4.
M is a bounded operator from \(L^{p,1}_\omega (\ell ^r,{\mathbb {R}}^n)\) to \(WM^{p}_{q,\omega }(\ell ^r,{\mathbb {R}}^n)\).
Proof
Note that Theorem 2 enables us to obtain the equivalence of (1) and (2). By Corollary 1, we immediately have (2) \(\Rightarrow \) (3) \(\Rightarrow \) (4). Therefore, to complete the proof of the theorem, we need to prove (4) \(\Rightarrow \) (1). For any cube Q, by the relation (6), we find a function f such that \(\Vert f\Vert _{L^{p,1}_\omega ({\mathbb {R}}^n)}\le 1\) and
It is obvious that \(Q=\{x\in Q: M(f)(x)>\lambda \}\), where \(\lambda =\frac{1}{2|Q|}\int _Q|f(x)|dx\). Thus, because M is a bounded operator from \(L^{p,1}_\omega ({\mathbb {R}}^n)\) to \(WM^{p}_{q,\omega }({\mathbb {R}}^n)\), we have
As a consequence, by (10), we give
From this, we have
This implies that \(\omega \in A(p,1)\), and the theorem is completely proved. \(\square \)
Next, we establish the boundedness results for pseudo-differential operators of order 0 on weighted Lorentz spaces. For \(m\in {\mathbb {R}}\), we say that the function \(a(x,\xi )\in C^{\infty }({\mathbb {R}}^n\times {\mathbb {R}}^n)\) is a symbol of order m if it satisfies the following inequality
for all multi-indices \(\alpha \) and \(\beta \), where \(C_{\alpha ,\beta } > 0\) is independent of x and \(\xi \). Then, a pseudo-differential operator is a mapping \(f\rightarrow T_{a}(f)\) given by
Remark that \(T_a\) is well defined on the space of Schwartz functions \(S({\mathbb {R}}^n)\) or on the space of all infinitely differentiable functions with compact support \(C^{\infty }_c({\mathbb {R}}^n)\), where \({{\widehat{f}}}\) is the Fourier transform of the function f.
Lemma 5
Let \(1< q \le p < \infty \), \(\omega \in A_p({\mathbb {R}}^n)\) and \(T_a\) be a pseudo-differential operator of order 0. Then, \(T_a\) extends to a bounded operator from \(L^{p,q}_\omega ({\mathbb {R}}^n)\) to \(L^{p,\infty }_\omega ({\mathbb {R}}^n)\).
Proof
By Theorem 2 and Theorem 4 in [7], we have
Next, by estimating as Theorem 2 in [18], we see that
Thus,
As mentioned above, since \(C^{\infty }_c({\mathbb {R}}^n)\) is dense in \(L^{p,q}_\omega ({\mathbb {R}}^n)\) (see Corollary 3.2 in [35]), we immediately have the desired result. \(\square \)
By using Lemma 5 and Corollary 1 and applying the Lorentz version Marcinkiewicz interpolation theorem as the proof of Theorem 3 in [7], we obtain the following useful result.
Theorem 6
Let \(1< p < \infty \), \(1<q\le \infty \), \(\omega \in A_p({\mathbb {R}}^n)\) and \(T_a\) be a pseudo-differential operator of order 0. Then, the following statements are true:
- 1.
\(T_a\) extends to a bounded operator from \(L^{p,q}_\omega ({\mathbb {R}}^n)\) to \(L^{p,q}_\omega ({\mathbb {R}}^n)\);
- 2.
\(T_a\) extends to a bounded operator from \(L^{p,q}_\omega ({\mathbb {R}}^n)\) to \(M^{p}_{q,\omega }({\mathbb {R}}^n)\);
- 3.
\(T_a\) extends to a bounded operator from \(L^{p,q}_\omega ({\mathbb {R}}^n)\) to \(WM^{p}_{q,\omega }({\mathbb {R}}^n)\).
For \(1< p < \infty \), by Lemma 1, we observe that \(\omega \in A(p,1)\) implies \(\omega \in {\varDelta }\). Thus, combining with Theorem 3.1 in [26], we can get the following result.
Theorem 7
If \(1< p< \infty , 0< \kappa < 1, \omega \in A(p,1)\), then the operator \(M_\omega \) is bounded on \({\mathcal {L}}^{q,\kappa }_\omega ({\mathbb {R}}^n)\).
Similarly to the known characterizations of the \(A_p\) weights given in [51], we also have another characterizations for the \(A_p(\varphi )\) weights as follows.
Theorem 8
Let either \(1< q< p < \infty \) or \(0< q < p = 1\). Then, the following statements are equivalent:
- 1.
\(\omega \in A_p(\varphi )\);
- 2.
\(M_\varphi \) is a bounded operator from \(L^{p}_\omega ({\mathbb {R}}^n)\) to \(L^{p,\infty }_\omega ({\mathbb {R}}^n)\);
- 3.
\(M_\varphi \) is a bounded operator from \(L^{p}_\omega ({\mathbb {R}}^n)\) to \(M^{p}_{q,\omega }({\mathbb {R}}^n)\);
- 4.
\(M_\varphi \) is a bounded operator from \(L^{p}_\omega ({\mathbb {R}}^n)\) to \(WM^{p}_{q,\omega }({\mathbb {R}}^n)\).
Proof
By Lemma 4 and Corollary 1, it is clear that the relation (1) \(\Leftrightarrow \) (2) and (2) \(\Rightarrow \) (3) \(\Rightarrow \) (4). Thus, to complete the proof, we need to prove the (4) \(\Rightarrow \) (1). More precisely, it is as the following.
In the case \(1< q< p < \infty \), let Q be any cube and take \(f_\varepsilon =(\omega +\varepsilon )^{1-p'}\chi _Q\), for all \(\varepsilon >0\), where \(p'\) is a conjugate real number of p, i.e \(\frac{1}{p}+\frac{1}{p'}=1\). It immediately follows that \(f_\varepsilon \in L^p_\omega ({\mathbb {R}}^n)\). For any \(0< \lambda < \frac{(\omega +\varepsilon )^{1-p'}(Q)}{\varphi (|Q|)|Q|}\), by letting \(x\in Q\), it is clear to see that
Hence, we obtain
Consequently, because \(M_\varphi \) is a bounded operator from \(L^p_\omega ({\mathbb {R}}^n)\) to \(WM^p_{q,\omega }({\mathbb {R}}^n)\), we infer
Thus, by choosing \(\lambda =\frac{(\omega +\varepsilon )^{1-p'}(Q)}{2\varphi (|Q|)|Q|}\), we get
which implies that
for all \(\varepsilon >0\). By letting \(\varepsilon \rightarrow 0^+\) and using dominated convergence theorem of Lebesgue, we obtain \(\omega \in A_p(\varphi )\).
In the case \(0< q < p = 1\), let us fix Q and take any cube \(Q_1 \subset Q\). Thus, we choose \(f = \chi _{Q_1}\). For any \(0< \lambda <\frac{|Q_1|}{\varphi (|Q|)|Q|}\), by estimating as (11) above, we immediately have
Next, by choosing \(\lambda =\frac{|Q_1|}{2\varphi (|Q|)|Q|}\), we infer
Hence, by the definition of operator \(M_\varphi \) and the Lebesgue differentiation theorem, it follows that
which gives \(\omega \in A_1(\varphi )\). \(\square \)
In final part of this section, we give the weighted norm inequality of weak type for new dyadic maximal operators \(M^{\varDelta }_{\varphi ,2\eta }\) on the vector valued Lebesgue spaces with weighted functions in \(A_p^{{\varDelta },\eta }(\varphi )\).
Theorem 9
If \(1< p< r < \infty , \omega \in A_p^{{\varDelta },\eta }(\varphi )\) for \(\eta >0\), then operator \(M^{\varDelta }_{\varphi ,2\eta }\) is bounded from \(L^p_\omega (\ell ^r,{\mathbb {R}}^n)\) to \(L^{p,\infty }_\omega (\ell ^r,{\mathbb {R}}^n)\).
Proof
Let \(\mathbf {f}\in \mathbf {S}\) and \(\alpha > 0\), where \(\mathbf {S}\) the linear space of sequences \(\mathbf {f} = \{f_k\}\) such that each \(f_k(x)\) is a simple function on \({\mathbb {R}}^n\) and \(f_k(x)\equiv 0\) for all sufficiently large k. By using Lemma 2.5 in [49], there exists a disjoint union of maximal dyadic cubes \(\{Q_j\}\) such that
Now, we compose \(\mathbf {f}=\mathbf {f'}+\mathbf {f^{''}}\), where \(\mathbf {f'}=\{f'_k\},f'_k(x)=f_k(x)\chi _{{\mathbb {R}}^n\backslash {\varOmega }}(x)\). This gives
As a consequence, we need to prove the following two results
and
By Lemma 3, for \(\omega \in A_p^{{\varDelta },\eta }(\varphi )\) we have
This implies that
Hence, by the Chebyshev inequality, it immediately follows that
On the other hand, by (12), we infer
which implies that, by (16), the inequality (14) holds.
It remains only to show that the inequality (15) is true. To estimate the inequality (15), we put \(\mathbf {{\overline{f}}}=\{{\overline{f}}_k \}\) as follows
Then, we obtain the important inequality as follows
Indeed, let \(x\notin {\varOmega }\) and Q be any dyadic cube such that \(x \in Q\). Thus, one has
where \(J = \{j \in {\mathbb {N}} : Q_j \cap Q \ne \emptyset \}\). Since \(\{Q_j\}\) and Q are dyadic cubes, and \(x \in Q\), we immediately have \(J = \{j \in {\mathbb {N}} : Q_j \subset Q\}\). Hence, we infer
On the other hand, we get
Therefore, by (18), one has
This implies that inequality (17) is true.
Next, for any \(x \in {\varOmega }\), there only exists a dyadic cube \(Q_j\) such that \(x \in Q_j\). Thus, by the Minkowski inequality and (13), we have
Hence, by using (17) and estimating as (16), it is clear to see that
which leads to
Besides that, by using (13), the Hölder inequality and \(\omega \in A_p^{{\varDelta },\eta }(\varphi )\), we get
From the above inequality, we infer
As an application, by (19), the proof for the inequality (15) is finished. Finally, since \(\mathbf {S}\) is dense in \(L^p_\omega (\ell ^r, {\mathbb {R}}^n)\) (see in [5]), the proof of the theorem is ended. \(\square \)
Next, we also obtain a necessary condition and a sufficient condition for the class of \(A_p^{{\varDelta },\eta }(\varphi )\) weights. More precisely, the following is true.
Theorem 10
Let \(1< q<p< r < \infty \) and \(\eta >0\). The following statements are true:
- (i)
If \(\omega \in A_p^{{\varDelta },\eta }(\varphi )\), then \(M^{\varDelta }_{\varphi ,2\eta }\) is a bounded operator from \(L^p_\omega (\ell ^r,{\mathbb {R}}^n)\) to \(L^{p,\infty }_\omega (\ell ^r,{\mathbb {R}}^n)\), \(M^{p}_{q,\omega }(\ell ^r,{\mathbb {R}}^n)\) and \(WM^{p}_{q,\omega }(\ell ^r,{\mathbb {R}}^n)\), respectively.
- (ii)
If \(\omega \notin A_p^{{\varDelta },\eta }(\varphi )\), then \(M^{\varDelta }_{\varphi ,\eta }\) is not a bounded operator from \(L^p_\omega (\ell ^r,{\mathbb {R}}^n)\) to \(WM^{p}_{q,\omega }(\ell ^r,{\mathbb {R}}^n)\).
Proof
By combining Theorem 9 and Corollary 1, the proof of (i) is finished. To prove (ii), we suppose that \(M^{\varDelta }_{\varphi ,\eta }\) is bounded from \(L^p_\omega (\ell ^r,{\mathbb {R}}^n)\) to \(WM^{p}_{q,\omega }(\ell ^r,{\mathbb {R}}^n)\). Then, by taking \(\mathbf {f}=\{f_k\}\), where \(f_k=0\) for all \(k\ge 2\), and the same argument as Theorem 8, we also obtain \(\omega \in A_p^{{\varDelta },\eta }(\varphi )\). \(\square \)
4 The results about the boundedness of sublinear operators generated by singular integrals and its commutators
Let us recall that the two weighted Morrey space \({\mathcal {M}}^{p,\kappa }_{\omega _1,\omega _2}(\ell ^r,{\mathbb {R}}^n)\) with vector-valued functions is defined as the set of all sequences of measurable functions \(\mathbf {f}=\{f_k\}\) such that
It is not difficult to show that \({\mathcal {M}}^{p,\kappa }_{\omega _1,\omega _2}(\ell ^r,{\mathbb {R}}^n)\) is a Banach space. Our first main result in this section is to give the boundedness of maximal singular integral operators with the kernels proposed by Anderson and John on the space \({\mathcal {M}}^{p,\kappa }_{\omega _1,\omega _2}(\ell ^r,{\mathbb {R}}^n)\). More precisely, we have the following useful result.
Theorem 11
Let \(1< r<\infty \), \(1<p<\infty \), \(\omega _1\in A(p,1)\), \(\omega _2\in A_p\), \(\delta \in (0,r_{\omega _2})\) and \(0<\kappa <\frac{\delta -1}{\delta p}\). Then, \(T^*\) is a bounded operator on \({\mathcal {M}}^{p,\kappa }_{\omega _1,\omega _2}(\ell ^r,{\mathbb {R}}^n)\).
Proof
Let us choose any \(\mathbf {f}\in {\mathcal {M}}^{p,\kappa }_{\omega _1,\omega _2}(\ell ^r,{\mathbb {R}}^n)\) and ball \(B_R(x_0):= B\). Next, we compose \(\mathbf {f}=\mathbf {f}_1+\mathbf {f}_2\), where \(\mathbf {f}_1=\{f_{1,k}\}\) such that \(f_{1,k}(x)=f_k(x)\chi _{2B}(x)\). This implies that
By Theorem 3 and Lemma 1, we have
Now, for \(x \in B\) and \(y \in (2B)^c\), it is clear to see that \(2R\le |x_0 - y| \le 2|x - y|\). From this, we get
for all \(k\in {\mathbb {N}}\). Hence, by the Minkowski inequality and the Hölder inequality and by assuming that \(\omega _2\in A_p\), we obtain
Thus,
where
Next, by applying Lemma 1, we have \( \big (\frac{\omega _1(2^{j+1}B)}{\omega _1(B)}\big )^{\frac{\kappa }{p}}\lesssim \big (\frac{|2^{j+1}B|}{|B|}\big )^{\kappa }\lesssim 2^{{(j+1)n\kappa }}. \) On the other hand, by Proposition 2, we infer
Hence, for \(\kappa <\frac{\delta -1}{\delta p}\), one has \( {\mathcal {K}}\lesssim \sum \limits _{j=1}^{\infty } 2^{(j+1)n(\kappa -\frac{\delta -1}{\delta p})}<\infty . \) Thus, \( J_2\lesssim \Vert \mathbf {f}\Vert ^p_{{\mathcal {M}}^{p,\kappa }_{\omega _1,\omega _2}(\ell ^r,{\mathbb {R}}^n)}. \) Combining this with (20) and (21) above, we obtain
which implies that the proof of the theorem is finished. \(\square \)
Remark that for the Hardy–Litlewood maximal operator, it is clear that
Thus, by the similar arguments as above, Theorem 11 is also true for the Hardy–Litlewood maximal operators. For the vector-valued maximal inequalities on generalized Morrey space such as weighted Orlicz–Morrey Spaces, see more details in [20].
Our second main result in this section is to establish the boundedness of sublinear operators generated by strongly singular operators on the weighted Morrey spaces. As an application, we obtain the boundedness of some strongly singular integral operators on the weighted Morrey spaces.
Let us recall the definition of the weighted central Morrey spaces. Let \(1 \le q< \infty , 0< \kappa < 1\) and \(\omega \) be a weighted function. Then the weighted central Morrey spaces is defined as the set of all functions in \(L^q_{{\mathrm{loc}}}({\mathbb {R}}^n)\) such that
It is evident that \(\mathcal {{\mathop M\limits ^.}}^{q,\kappa }(\omega , {\mathbb {R}}^n)\) is a Banach space. We denote by \(\mathfrak {\mathop M\limits ^.}^{q,\kappa }(\omega , {\mathbb {R}}^n)\) the closure of \(L^{q}({\mathbb {R}}^n)\cap \mathcal {{\mathop M\limits ^.}}^{q,\kappa }(\omega , {\mathbb {R}}^n)\) with respect to the norm in \(\mathcal {{\mathop {M}\limits ^{.}}}^{q,\kappa }(\omega , {\mathbb {R}}^n)\). It should be pointed out that the Morrey space is properly wider than the Lebesgue space, and \(L^q\cap {\mathcal {M}}^{q,\kappa }\), in general, is not dense in \({\mathcal {M}}^{q,\kappa }\) (see [41, 53]).
We also recall that the central weighted local Morrey spaces \(\mathcal {\mathop M\limits ^.}^{q,\kappa }_{{\mathrm{loc}}}(\omega ,{\mathbb {R}}^n)\) as the set of all functions in \(L^q_{{\mathrm{loc}}}({\mathbb {R}}^n)\) such that
Theorem 12
Let \(1<p<\infty \), \(\lambda >0\), \(0<\kappa <1\), and \(\omega (x)=|x|^{\beta }\) for \(-n+\frac{\lambda p}{\kappa }<\beta < \frac{\lambda p +(1-\kappa )n}{\kappa }\) and \(\kappa _1\in (0,\kappa -\frac{\lambda p}{n+\beta }]\). Then, the following is true:
(i) If \({\mathcal {T}}\) extends to a bounded operator on \(L^p({\mathbb {R}}^n)\), then \({\mathcal {T}}\) can also extend to a bounded operator from \(\mathfrak {\mathop M\limits ^.}^{p,\kappa }(\omega ,{\mathbb {R}}^n)\) to \(\mathcal {{\mathop M\limits ^.}}^{p,\kappa _1}_{{\mathrm{loc}}}(\omega , {\mathbb {R}}^n)\).
(ii) Let \(b \in L^{\eta }_{{\mathrm{loc}}}({\mathbb {R}}^n)\cap BMO({\mathbb {R}}^n)\) with \(\eta >p'\). If the commutator \([b, {\mathcal {T}}]\) extends to a bounded operator on \(L^p({\mathbb {R}}^n)\), then it can also extend to a bounded operator from \(\mathfrak {\mathop M\limits ^.}^{p,\kappa }(\omega ,{\mathbb {R}}^n)\) to \(\mathcal {{\mathop M\limits ^.}}^{p,\kappa _1}_{{\mathrm{loc}}}(\omega , {\mathbb {R}}^n)\).
Proof
It is sufficient to prove the theorem for all \(f\in L^p({\mathbb {R}}^n)\cap \mathcal {{\mathop M\limits ^.}}^{p,\kappa }(\omega , {\mathbb {R}}^n)\).
(i) By fixing a ball \(B_R(x_0):=B\) (for \(x_0=0\)), with \(0<R<1\) and decomposing \(f=f_1+f_2\), where \(f_1= f.\chi _{2B}\), one has
To estimate \(I_1\), because \({\mathcal {T}}\) extends to a bounded operator on \(L^p({\mathbb {R}}^n)\) and the inequality (5), we have
On the other hand, since \(f_2\in L^{p}({\mathbb {R}}^n)\), one has that \(g_m =f.\chi _{(2B)^c\cap {(2mB)}}\rightarrow f_2\) in \(L^p({\mathbb {R}}^n)\). Thus, by assuming that \({\mathcal {T}}\) is bounded on \(L^p({\mathbb {R}}^n)\) again, there exists a subsequence \(({\mathcal {T}}(g_{m_k}))\)-denoted by \(({\mathcal {T}}(g_m))\) such that \({\mathcal {T}}(g_m)\rightarrow {\mathcal {T}}(f_2)\) a.e on \({\mathbb {R}}^n\). From this, noting that \({\mathcal {T}}\) still satisfies the inequality (3) on \(L^{p}_{\mathrm{comp}} ({\mathbb {R}}^n)\) (the space of all \(L^{p} ({\mathbb {R}}^n)\)-functions with compact support) and letting \(x\in B\) with m large enough, we obtain
Notice that let \(x\in B\) and \(y\in (2B)^c\), we have \(2R\le |x_0 - y|\le 2|x - y|\). This implies that
From this, by the Hölder inequality, we deduce
As a consequence, by (5), we give
Therefore, by (22) and (23), we immediately have
which gives that the proof of part (i) is ended.
(ii) As the proof of part (i) above, we also fix a ball \(B_R(x_0):=B\) (for \(x_0=0\)) with \(0<R<1\), and write \(f=f_1+f_2\) with \(f_1= f.\chi _{2B}\). Thus, we get
Next, because \([b, {\mathcal {T}}]\) extends to a bounded operator on \(L^p({\mathbb {R}}^n)\) and using the relation (5) again, we obtain
Next, by \(b\in L^{\eta }_{{\mathrm{loc}}}({\mathbb {R}}^n)\) with \(\eta > p'\) and the inequality (4), we get
Thus, by estimating as (24) above and letting \(x\in B\) and \(y\in (2B)^c\), we have
This leads to that
For the term \(K_{2,1}\), by using (25), (26), (27) and Lemma 2, we infer
For the term \(K_{2,2}\), by the Hölder inequality, we have
where \(L_{1,i}=\Big (\int _{2^{j+1}B}|b(y)-b_{2^{j+1}B}|^{p'}dy\Big )^{\frac{1}{p'}}\) and \(L_{2,i}=\Big (\int _{2^{j+1}B}|b_B-b_{2^{j+1}B}|^{p'}dy\Big )^{\frac{1}{p'}}\). On the other hand, by Lemma 2 and Proposition 1, we also get
and
Thus, by estimating as (27) above, we immediately have
From the above estimation, by (28)–(31), we confirm
Therefore, the proof of this theorem is completed. \(\square \)
Now, let us give some applications of Theorem 12. Note that Hirschman [23], Wainger [52, p 80], Cho and Yang [11] studied the strongly singular convolution operators in the context of \(L^p({\mathbb {R}}^n)\) spaces defined as follows.
Definition 12
Let \(0< s < \infty \) and \(0< \lambda < \frac{ns}{2}\). The strongly singular integral operator \(T^{s,\lambda }\) is defined by
Theorem 13
(see in [15, 23, 52]) Let \(0<s<\infty \), \(1<p<\infty \), \(0<\lambda <\frac{ns}{2}\), \(|\frac{1}{p}-\frac{1}{2}|<\frac{1}{2}-\frac{\lambda }{ns}\). Then \(T^{s,\lambda }\) extends to a bounded operator from \(L^p({\mathbb {R}}^n)\) to itself.
Definition 13
Let \(0< \zeta , s,\lambda < \infty \), and k be an integer with \(k\ge 2\). The strongly singular integral operator \(T_{\zeta ,s,\lambda }\) is defined by
Theorem 14
(see in [11]) Let \(0< \zeta , s, \lambda < \infty \), \(k\in {\mathbb {N}}\) with \(k\ge 2\) and \(s\ge 2\lambda \). Then \(T_{\zeta ,s,\lambda }\) extends to a bounded operator from \(L^2({\mathbb {R}})\) to itself.
On the other hand, Li and Lu [29] also studied the Coifman–Rochberg–Weiss type commutator of strongly singular integral operator defined as follows
Definition 14
Let \(0< s < \infty \) and \(0< \lambda < \frac{ns}{2}\). The Coifman–Rochberg–Weiss type commutator of strongly singular integral operator is defined by
where b is locally integrable functions on \({\mathbb {R}}^n\).
Moreover, Li and Lu [29] proved the following interesting result.
Theorem 15
(Theorem 1.1 [29]) Let \(0< s < \infty \), \(1<p<\infty \), \(0<\lambda <\frac{ns}{2}\), \(|\frac{1}{p}-\frac{1}{2}|<\frac{1}{2}-\frac{\lambda }{ns}\) and \(b\in BMO({\mathbb {R}}^n)\). Then the commutator \([b, T^{s,\lambda }]\) extends to a bounded operator on \(L^p({\mathbb {R}}^n)\).
From Theorems 12, 13, 14 and 15, we obtain the useful results as follows.
Corollary 2
Let \(0<s<\infty \), \(1<p<\infty \), \(0<\lambda <\frac{ns}{2}\), \(0<\kappa <1\), \(|\frac{1}{p}-\frac{1}{2}|<\frac{1}{2}-\frac{\lambda }{ns}\), \(-n+\frac{\lambda p}{\kappa }< \beta < \frac{\lambda p +(1-\kappa )n}{\kappa }\), \(\omega (x)=|x|^{\beta }\) and \(\kappa _1\in (0,\kappa -\frac{\lambda p}{n+\beta }]\). Let \(b\in L^{\eta }_{{\mathrm{loc}}}({\mathbb {R}}^n)\cap BMO({\mathbb {R}}^n)\) with \(\eta >p'\). Then \(T^{s,\lambda }\) and \([b, T^{s,\lambda }]\) extend to bounded operators from \(\mathfrak {\mathop M\limits ^.}^{p,\kappa }(\omega ,{\mathbb {R}}^n)\) to \(\mathcal {\mathop M\limits ^.}^{p,\kappa _1}_{{\mathrm{loc}}}(\omega ,{\mathbb {R}}^n)\).
Corollary 3
Let \(0<\zeta ,\lambda ,s<\infty \), \(k\in {\mathbb {N}}\) with \(k\ge 2\), \(s\ge 2\lambda \), \(0<\kappa <1\), \(-1+\frac{2\lambda }{\kappa }< \beta < \frac{2\lambda +(1-\kappa )}{\kappa }\), \(\omega (x)=|x|^{\beta }\) and \(\kappa _1\in (0,\kappa -\frac{2\lambda }{1+\beta }]\). Then \(T_{\zeta , s,\lambda }\) extends to a bounded operator from \(\mathfrak {\mathop M\limits ^.}^{2,\kappa }(\omega ,{\mathbb {R}})\) to \(\mathcal {\mathop M\limits ^.}^{2,\kappa _1}_{{\mathrm{loc}}}(\omega ,{\mathbb {R}})\).
Remark that in the special case when the weight function in Theorem 12, Corollary 2 and Corollary 3 is a constant function, then we can remove “.” in the spaces, that is, we may replace \(\mathfrak {\mathop M\limits ^.}^{p,\kappa }({\mathbb {R}}^n)\) and \(\mathcal {\mathop M\limits ^.}^{p,\kappa _1}_{{\mathrm{loc}}}({\mathbb {R}}^n)\) by \({\mathfrak {M}}^{p,\kappa }({\mathbb {R}}^n)\) and \({\mathcal {M}}^{p,\kappa _1}_{{\mathrm{loc}}}({\mathbb {R}}^n)\), respectively. Here \({{\mathfrak {M}} }^{p,\kappa }({\mathbb {R}}^n)\) is the closure of \(L^{p}({\mathbb {R}}^n)\cap {{\mathcal {M}}}^{p,\kappa }({\mathbb {R}}^n)\) in the space \({{\mathcal {M}}}^{p,\kappa }( {\mathbb {R}}^n)\).
Finally, we give the boundedness of sublinear operators in the setting when the weighted function is in the class of Muckenhoupt weights. It is worth pointing out that when \(\omega _1=\omega _2=\omega \), then the space \(C^\infty _0({\mathbb {R}}^n)\) is contained in \({{\mathcal {M}}}^{q,\kappa }_\omega ({\mathbb {R}}^n)\). The space \({{\mathfrak {M}} }^{q,\kappa }_\omega ({\mathbb {R}}^n)\) is denoted as the closure of \(L^{q}({\mathbb {R}}^n)\cap {{\mathcal {M}}}^{q,\kappa }_\omega ({\mathbb {R}}^n) \) in the space \({{\mathcal {M}}}^{q,\kappa }_\omega ({\mathbb {R}}^n)\).
Theorem 16
Let \(1<p<\infty \), \(0<\kappa <1\), and \(1\le p^*,\zeta <\infty \), \(\omega \in A_{\zeta }\) with the finite critical index \(r_\omega \) for the reverse Hölder. Assume that \(p > p^{*}\zeta {r^{'}_\omega }, \delta \in (1,r_\omega )\) and \(\kappa ^*=\frac{p^*(\kappa -1)}{p}+1\). Then, if \({\mathcal {T}}\) extends to a bounded operator on \(L^p({\mathbb {R}}^n)\), then \({\mathcal {T}}\) can also extend to a bounded operator from \({{\mathfrak {M}} }^{p,\kappa }_\omega ({\mathbb {R}}^n)\) to \({M}^{p^*,\kappa ^*}_\omega ({\mathbb {R}}^n)\).
Proof
Let us fix \(f\in L^{p}({\mathbb {R}}^n)\cap {{\mathcal {M}}}^{p,\kappa }_\omega ({\mathbb {R}}^n)\) and a ball \(B_R(x_0):=B\) with \(R\ge 1\). From assuming that \(p > p^*\zeta r^{'}_\omega \), one has \(r\in (1, r_\omega )\) satisfying \(p = \zeta p^* r'\). Hence, by the Hölder inequality and the reverse Hölder condition, we lead to
Next, we decompose \(f=f_1+f_2\) where \(f_1=f.\chi _{2B}\). Thus,
From assuming that \({\mathcal {T}}\) extends to a bounded operator on \(L^p({\mathbb {R}}^n)\) and using Proposition 3, we get
Next, let us give \(x\in B\) and \(y\in (2B)^c\). By applying the relation (24) above and estimating as (25) and (35), we obtain
Hence,
Next, by Proposition 2 and \(\kappa \in (0,1)\), we deduce
From this, by using (33)–(36), \(\kappa ^*=\frac{p^*(\kappa -1)}{p}+1\) and \(R\ge 1\), we get
Therefore,
This implies that the theorem is proved. \(\square \)
By Theorem 16, we obtain the following interesting corollary.
Corollary 4
Let \(s,\lambda ,\kappa ,p\) as Corollary 2 and \(1\le p^*,\zeta <\infty \), \(\omega \in A_{\zeta }\) with the finite critical index \(r_\omega \) for the reverse Hölder. Assume that \(p > p^{*}\zeta {r^{'}_\omega }, \delta \in (1,r_\omega )\) and \(\kappa ^*=\frac{p^*(\kappa -1)}{p}+1\). Then, \(T^{s,\lambda }\) can extend to a bounded operator from \({{\mathfrak {M}} }^{p,\kappa }_\omega ({\mathbb {R}}^n)\) to \({M}^{p^*,\kappa ^*}_\omega ({\mathbb {R}}^n)\).
References
Adams, D.R.: A note on Riesz potentials. Duke Math. J. 4(2), 765–778 (1975)
Álvarez, J., Milman, M.: Vector valued inequalities for strongly Calderón–Zygmund operators. Rev. Mat. Iberoam. 2, 405–426 (1986)
Alvarez, J., Guzmán-Partida, M., Lakey, J.: Spaces of bounded \(\lambda \)-central mean oscillation, Morrey spaces, and \(\lambda \)-central Carleson measures. Collect. Math. 51, 1–47 (2000)
Andersen, K., John, R.: Weighted inequalities for vector-valued maximal functions and singular integrals. Studia Math. 69(1), 19–31 (1981)
Benedek, A., Panzone, R.: The space \(L^p\) with mixed norm. Duke Math. J. 28, 301–324 (1961)
Caffarelli, L.: Elliptic second order equations. Rend. Sem. Mat. Fis. Milano. 58, 253–284 (1988)
Chung, H.M., Hunt, R.A., Kurtz, D.S.: The Hardy–Littlewood maximal function on \(L(p, q)\) spaces with weights. Indiana Univ. Math. J. 31(1), 109–120 (1982)
Chuong, N.M.: Pseudodifferential operators and wavelets over real and p-adic fields. Springer, Berlin (2018)
Chuong, N.M., Duong, D.V., Dung, K.H.: Vector valued maximal Carleson type operators on the weighted Lorentz spaces (2017), arXiv:1707.00092v1
Coifman, R., Fefferman, C.: Weighted norm inequalities for maximal functions and singular integrals. Studia Math. 51(3), 241–250 (1974)
Cho, C.H., Yang, C.W.: Estimates for oscillatory strongly singular integral operators. J. Math. Anal. Appl. 362, 523–533 (2010)
Duoandiotxea, J., Rosenthal, M.: Extension and boundedness of operators on Morrey spaces from extrapolation techniques and embeddings. J. Geom. Anal. 28(4), 3081–3108 (2018)
Fan, D., Lu, S., Yang, D.: Regularity in Morrey spaces of strong solutions to nondivergence elliptic equations with VMO coefficients. Georgian Math. J. 5(5), 425–440 (1998)
Fefferman, C., Stein, E.M.: Some maximal inequalities. Am. J. Math. 93(1), 107–115 (1971)
Fefferman, C.: Inequality for strongly singular convolution operators. Acta Math. 124, 9–36 (1970)
Federbush, P.: Navier and Stokes meet the wavelet. Commun. Math. Phys. 155, 219–248 (1993)
Guliyev, V.S., Aliyev, S.S., Karaman, T., Shukurov, P.S.: Boundedness of sublinear operators and commutators on generalized Morrey spaces. Integr. Equ. Oper. Theory 71, 327–355 (2011)
Gurbuz, F.: Weighted Morrey and weighted fractional Sobolev–Morrey spaces estimates for a large class of pseudo-differential operators with smooth symbols. J. Pseudo-Differ. Oper. Appl. 7, 595–607 (2016)
Grafakos, L.: Modern Fourier Analysis, 2nd edn. Springer, Berlin (2008)
Ho, K.P.: Vector-valued maximal inequalities on weighted Orlicz–Morrey spaces. Tokyo J. Math. 36(2), 499–512 (2013)
Hunt, R.A.: On L(p, q) spaces. Enseign. Math. 12, 249–276 (1966)
Hytönen, T., Pérez, C., Rela, E.: Sharp reverse Hölder property for \(A_\infty \) weights on spaces of homogeneous type. J. Funct. Anal. 263, 3883–3899 (2012)
Hirschman, I.I.: On multiplier transformations. Duke Math. J. 26, 221–242 (1959)
Indratno, S., Maldonado, D., Silwal, S.: A visual formalism for weights satisfying reverse inequalities. Expo. Math. 33, 1–29 (2015)
Kaneko, M., Yano, S.: Weighted norm inequalities for singular integrals. J. Math. Soc. Jpn. 27, 570–588 (1975)
Komori, Y., Shirai, S.: Weighted Morrey spaces and a singular integral operator. Math. Nachr. 282, 219–231 (2009)
Kokilashvili, V., Meskhi, A., Rafeiro, H.: Sublinear operators in generalized weighted Morrey spaces. Dokl. Math. 94, 558–560 (2016)
Lorentz, G.G.: Some new functional spaces. Ann. Math. 51(1), 37–55 (1950)
Li, J., Lu, S.: \(L^p\) estimates for multilinear operators of strongly singular integral operators. Nagoya Math. J. 181, 41–62 (2006)
Lin, Y.: Strongly singular Calderón–Zygmund operator and commutator on Morrey type spaces. Acta Math. Sin. 23, 2097–2110 (2007)
Mazzucato, A.L.: Besov–Morrey spaces: function space theory and applications to non-linear PDE. Trans. Am. Math. Soc. 355(4), 1297–1364 (2003)
Mastylo, M., Sawano, Y., Tanaka, H.: Morrey type space and its Köthe dual space. Bull. Malays. Math. Soc. 41, 1181–1198 (2018)
Muckenhoupt, B.: Weighted norm inequalities for the Hardy maximal function. Trans. Am. Math. Soc. 165, 207–226 (1972)
Morrey, C.: On the solutions of quasi-linear elliptic partial differential equations. Trans. Am. Math. Soc. 43, 126–166 (1938)
Nakai, E., Tomita, N., Yabuta, K.: Density of the set of all infinitely differentiable functions with compact support in weighted Sobolev spaces. Sci. Math. Jpn. Online. 10, 39–45 (2004)
Nakai, E.: Hardy–Littlewood maximal operator, singular integral operators and the Riesz potentials on generalized Morrey spaces. Math. Nachr. 166, 95–103 (1994)
Nakamura, S., Sawano, Y.: The singular integral operator and its commutator on weighted Morrey spaces. Collect. Math. 68(2), 145–174 (2017)
Pérez, C.: Endpoints for commutators of singular integral operators. J. Funct. Anal. 128, 163–185 (1995)
Pan, Y.: Hardy spaces and oscillatory singular integrals. Rev. Mat. Iberoam. 7, 55–64 (1991)
Ruiz, A., Vega, L.: Unique continuation for Schrödinger operators with potential in Morrey spaces. Publ. Mat. 35(1), 291–298 (1991)
Sawano, Y., Tanaka, H.: The Fatou property of block spaces. J. Math. Sci. Univ. Tokyo 22(3), 663–683 (2015)
Samko, N.: Weighted Hardy and singular operators in Morrey spaces. J. Math. Anal. Appl. 350(1), 56–72 (2009)
Shen, Z.: The periodic Schrödinger operators with potentials in the Morrey class. J. Funct. Anal. 193(2), 314–345 (2002)
Soria, F., Weiss, G.: A remark on singular integrals and power weights. Indiana Univ. Math. J. 43, 187–204 (1994)
Stein, E.M.: Harmonic Analysis: Real-Variable Methods, Orthogonality, and Oscillatory Integrals. Princeton University Press, Princeton (1993)
Sjölin, P.: \(L^p\) estimates for strongly singular convolution operators in \({\mathbb{R}}^n\). Ark. Mat. 14, 59–64 (1976)
Tanaka, H.: Two-weight norm inequalities on Morrey spaces. Ann. Acad. Sci. Fenn. Math. 40(2), 773–791 (2015)
Torchinsky, A.: Real Variable Methods in Harmonic Analysis. Academic Press, San Diego (1986)
Tang, L.: Weighted norm inequalities for pseudodifferential operators with smooth symbols and their commutators. J. Funct. Anal. 262, 1603–1629 (2012)
Taylor, M.E.: Analysis on Morrey spaces and applications to Navier–Stokes and other evolution equations. Commun. Partial Differ. Equ. 17, 1407–1456 (1992)
Wang, D., Zhou, J., Chen, W.: Another characterizations of Muckenhoupt \(A_p\) class. Acta Math. Sci. 37, 1761–1774 (2017)
Wainger, S.: Special trigonometric series in k-dimensions. Mem. Am. Math. Soc. 56 (1965)
Zorko, C.T.: Morrey space. Proc. Am. Math. Soc. 98, 586–592 (1986)
Acknowledgements
The authors are grateful to the anonymous referee for the valuable suggestions and comments which lead to the improvement of the paper. The authors are supported by the Vietnam National Foundation for Science and Technology Development (NAFOSTED) under Grant No 101.02-2014.51.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Minh Chuong, N., Van Duong, D. & Huu Dung, K. Maximal operators and singular integrals on the weighted Lorentz and Morrey spaces. J. Pseudo-Differ. Oper. Appl. 11, 201–228 (2020). https://doi.org/10.1007/s11868-019-00277-3
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11868-019-00277-3
Keywords
- Maximal function
- Sublinear operator
- Strongly singular integral
- Commutator
- \(A_p\) weight
- \(A(p{, } 1)\) weight
- \(A_p(\varphi )\) weight
- BMO space
- Lorentz spaces
- Morrey spaces