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Commutators of multilinear fractional maximal operators with Lipschitz functions on Morrey spaces

  • Pu Zhang and Müjdat Ağcayazı EMAIL logo
Published/Copyright: October 15, 2024

Abstract

In this work, we present necessary and sufficient conditions for the boundedness of the commutators generated by multilinear fractional maximal operators on the products of Morrey spaces when the symbol belongs to Lipschitz spaces.

MSC 2010: 47B47; 42B25; 42B35; 46E30

1 Introduction and main results

Let T be a Calderón-Zygmund singular integral operator. In 1976, Coifman et al. [1] studied the commutator generated by T and a suitable function b as follows:

(1) [ T , b ] f ( x ) T ( b f ) ( x ) b ( x ) T f ( x ) .

A well-known result states that [ T , b ] is bounded on L p ( R n ) for 1 < p < if and only if b BMO ( R n ) . Sufficiency was proved by Coifman et al. [1] and necessity part was obtained by Janson [2].

In 1978, Janson [2] gave some characterizations of Lipschitz space Λ ˙ β ( R n ) via commutator [ T , b ] and proved that b Λ ˙ β ( R n ) ( 0 < β < 1 ) if and only if [ T , b ] is bounded from L p ( R n ) to L q ( R n ) , where 1 < p < n β and 1 p 1 q = β n [3].

Let 0 α < n . The fractional maximal operator M α is defined by

M α f ( x ) = sup Q x 1 Q 1 α n Q f ( y ) d y ,

where the supremum is taken over all the cubes Q R n containing x with sides parallel to the coordinate axes and where f is any locally integrable function. When α = 0 , M 0 M is known as the Hardy-Littlewood maximal operator.

In order to investigate [ M α , b ] , we start with the consideration of the fractional maximal commutators M b , α .

Definition 1

Let 0 α < n . Given a measurable function b , the fractional maximal commutators M b , α are defined by

M b , α ( f ) ( x ) sup Q x 1 Q 1 α n Q b ( x ) b ( y ) f ( y ) d y , ( x R n ) .

This type of operator plays an important role in the study of commutators of singular integral operators with bounded mean oscillation (BMO) symbols [46]. Segovia and Torrea [6, Theorem 3.5] proved that if b BMO ( R n ) , 0 < α < n , 1 p 1 q = α n , w A p , q , then M b , α is bounded from L p ( w p ) to L q ( w q ) . In general, M b , α fails to be weak type ( 1 , n ( n α ) ) when b BMO ( R n ) . Instead, an endpoint theory was provided for this operator such as weak type L ( 1 + log + L ) , see for instance [7, Theorem 3].

Similar to (1), we can recall the definition of commutators of fractional maximal operators as follows:

Definition 2

Let 0 α < n . Given a measurable function b , the commutators of the fractional maximal operators M α and b are defined by

[ M α , b ] f ( x ) M α ( b f ) ( x ) b ( x ) M α f ( x ) .

We would like to point out that operators M b , α and [ M α , b ] are essentially different from each other. For example, M b , α is positive and sublinear, but [ M α , b ] is neither positive nor sublinear.

Mapping properties of M b , α and [ M α , b ] have been studied extensively by many authors for BMO functions and remarkable results have been obtained in Lebesgue spaces, weighted Lebesgue spaces, variable Lebesgue spaces, Orlicz spaces, and Morrey spaces, [813].

Zhang et al. [14] gave some necessary and sufficient conditions for the boundedness of M b , α and [ M α , b ] on variable Lebesgue spaces L p ( ) ( R n ) when the nonnegative symbol b belongs to Lipschitz spaces, which gives some new characterizations for certain subclasses of Lipschitz spaces. The first necessary and sufficient conditions of Lipschitz functions on Orlicz spaces L Φ ( R n ) were given by Guliyev et al. [15] when 0 α < n , and Zhang [16] obtained new characterizations of non-negative Lipschitz functions on Orlicz spaces by extending and improving the results in [15].

Multilinear Calderón-Zygmund operators (CZOs) were introduced and first studied by Coifman and Meyer [17], and later on by Grafakos and Torres [18] as a natural generalization of the linear case. In recent years, the theory of multilinear CZOs and related operators such as multilinear singular integral operators, maximal and fractional maximal type operators, and fractional integrals have attracted much attention [1923].

Commutators of multilinear operators with BMO symbols have also been studied extensively by many authors, and some important theorems obtained in linear cases, such as boundedness and endpoint theorems, have also been obtained for these operators [24,25].

Definition 3

Let 0 α < m n , f = ( f 1 , f 2 , , f m ) be locally integrable functions. The multilinear fractional maximal function α is defined by

(2) α ( f ) ( x ) = sup Q x i = 1 m 1 Q 1 α m n Q f i ( y i ) d y i ,

where the supremum is taken over all the cubes Q R n containing x .

When α = 0 , 0 is exactly the multilinear maximal function, simply denoted by , introduced by Lerner et al. [20] to adopt to multiple weight theory of CZOs. In [20] Lerner et al. developed a multiple weight theory that adopts to the multilinear CZOs. When 0 < α < m n , α is the multilinear fractional maximal function considered by Chen and Xue [26] and Moen [22] in studying the multiple weight theory of multilinear fractional integral operator.

Similar to linear case, we can define the maximal and the nonlinear commutators of α .

For notational convenience, we will occasionally write f = ( f 1 , , f m ) , y = ( y 1 , , y m ) , and d y = d y 1 d y m . We also use b = ( b 1 , , b m ) ( Λ ˙ β ) m to stand for b j Λ ˙ β for j = 1 , , m , where Λ β is the Lipschitz space (see Definition 5). For a measurable set E , we denote by E the Lebesgue measure of E and by χ E the characteristic function of E and write E m = ( E ) m = E × × E m and χ E = ( χ E , , χ E m ) .

Definition 4

Let 0 α < m n , f = ( f 1 , f 2 , , f m ) , and b = ( b 1 , b 2 , b m ) be two collections of locally integrable functions. The maximal commutator of α with b is given by

α , b ( f ) ( x ) = i = 1 m α , b i ( f ) ( x ) ,

where

α , b i ( f ) ( x ) = sup Q x 1 Q m α n Q m b i ( x ) b i ( y i ) j = 1 m f j ( y j ) d y .

The nonlinear commutator of α with b is defined by

[ b , α ] ( f ) ( x ) = i = 1 m [ b , α ] i ( f ) ( x ) ,

where

[ b , α ] i ( f ) ( x ) = b i ( x ) α ( f ) ( x ) α ( f 1 , , b i f i , , f m ) ( x ) .

When α = 0 , we simply write b instead of 0 , b and [ b , ] instead of [ b , 0 ] . We note that the operators α , b and [ b , α ] essentially differ from each other. For example α , b is positive and sublinear in each entry, but [ b , α ] is neither positive nor sublinear.

In 2015, Zhang [27] first considered mapping properties of commutators b and [ b , ] when the symbols belong to BMO. More clearly, the multiple weighted strong, and weak-type estimates for these operators are studied and some necessary and sufficient conditions for the boundedness of these operators are given. Wang and Wang [28] established characterizations of the weighted BMO space in terms of several different commutators of bilinear Hardy-Littlewood maximal function b and [ b , ] . Yu et al. [29] considered equivalent conditions for the boundedness of the commutators b and [ b , ] generated by the multilinear maximal function and the BMO functions on Morrey spaces. Moreover, the endpoint estimate for such operators on generalized Morrey spaces is also given. Zhang [30] gave some necessary and sufficient conditions for boundedness for the maximal and nonlinear commutators of a multi-sublinear maximal function α with symbols belonging to Lipschitz spaces.

In this study, we present necessary and sufficient conditions for the boundedness of the commutators α , b and [ b , α ] on the product of Morrey spaces when the symbol belongs to Lipschitz functions.

Definition 5

Let β ( 0 , 1 ) . Then, a function b belongs to Lipschitz space Λ ˙ β ( R n ) if there exists a constant c > 0 such that for all x , y R n ,

b ( x ) b ( y ) c x y β .

The smallest such constant c is called Λ ˙ β norm of b and is denoted by b Λ ˙ β ( R n ) .

We may now formulate our main results for the maximal commutators α , b first, and then for the commutators of the maximal functions [ b , α ] on Morrey spaces as follows.

Theorem 1

Let 0 < β < 1 , 0 α < m n , 0 < α + β < m n , and b = ( b 1 , b 2 , , b m ) be a collection of locally integrable functions. Suppose that 1 < p 1 , , p m < , 1 p = 1 p 1 + + 1 p m , p j < m n α + β , p > 1 , λ p = j = 1 m λ j p j , 1 q j = 1 p j α + β m ( n λ j ) , 0 λ j < n ( α + β ) p j m , and 1 q = 1 p α + β n λ . Then, the following assertions are equivalent:

  1. b ( Λ ˙ β ) m .

  2. α , b is bounded from L p 1 , λ 1 ( R n ) × × L p m , λ m ( R n ) to L q , λ ( R n ) .

Theorem 2

Let 0 < β < 1 , 0 α < m n , 0 < α + β < m n , and b = ( b 1 , b 2 , , b m ) be a collection of locally integrable functions. Suppose that 1 < p 1 , , p m < , 1 = 1 p 1 + + 1 p m , p j < m n α + β , q > 1 , λ = j = 1 m λ j p j , 1 q j = 1 p j α + β m ( n λ j ) , 0 λ j < n ( α + β ) p j m , and 1 q = 1 α + β n λ . Then, the following assertions are equivalent:

  1. b ( Λ ˙ β ) m .

  2. α , b is bounded from L p 1 , λ 1 ( R n ) × × L p m , λ m ( R n ) to W L q , λ ( R n ) .

Theorem 3

Let 0 < β < 1 , 0 α < m n , 0 < α + β < m n , and b = ( b 1 , b 2 , , b m ) be a collection of locally integrable functions. Suppose that 1 < p 1 , , p m < , 1 p = 1 p 1 + + 1 p m , p j < m n α + β , p > 1 , λ p = j = 1 m λ j p j , 1 q j = 1 p j α + β m ( n λ j ) , 0 λ j < n ( α + β ) p j m , and 1 q = 1 p α + β n λ .

  1. If b ( Λ ˙ β ) m and b j 0 for j = 1 , 2 , , m , then [ b , α ] is bounded from L p 1 , λ 1 ( R n ) × × L p m , λ m ( R n ) to L q , λ ( R n ) .

  2. If q 1 and [ b , α ] j is bounded from L p 1 , λ 1 ( R n ) × × L p m , λ m ( R n ) to L q , λ ( R n ) , then b j Λ ˙ β ( R n ) and b j 0 .

Theorem 4

Let 0 < β < 1 , 0 α < m n , 0 < α + β < m n , and b ( Λ ˙ β ) m and b j 0 for j = 1 , 2 , , m . Suppose that 1 < p 1 , , p m < , 1 = 1 p 1 + + 1 p m , p j < m n α + β , q > 1 , λ = j = 1 m λ j p j , 1 q j = 1 p j α + β m ( n λ j ) , 0 λ j < n ( α + β ) p j m , and 1 q = 1 α + β n λ . Then [ b , α ] is bounded from L p 1 , λ 1 ( R n ) × × L p m , λ m ( R n ) to W L q , λ ( R n ) .

Remark 1

When λ = 0 , since Morrey space reduces to Lebesgue space, note that Theorems 14 cover Zhang’s results in [30].

The rest of the work is organized as follows: Section 2 contains some lemmas and definitions necessary to prove the main theorems. In Section 3, we prove Theorems 12 and the proof of Theorems 34 will be given in the the final section.

2 Notations and preliminaries

Throughout the work, we always denote by c a positive constant, which is independent of main parameters but it may vary from line to line. By a b , we mean that a c b , where c > 0 depends on inessential parameters.

As usual, for a locally integrable function f and a cube Q , f Q denotes the usual average of f over Q f Q = 1 Q Q f .

Let β ( 0 , 1 ) and 1 q < . We can characterize the Lipschitz (Campanato) space Λ ˙ β , q ( R n ) . Recall that the Lipschitz (Campanato) space Λ ˙ β , q ( R n ) is the set of all f L l o c p ( R n ) for which the quantity

sup Q Q β n 1 Q Q b ( y ) b Q q d y 1 q c < .

Then, for all β ( 0 , 1 ) and 1 q < , Λ ˙ β , q ( R n ) = Λ ˙ β ( R n ) with equivalent norms [3,31,32]. We know also that there exists a constant c β , q such that

(3) b Λ ˙ β , 1 ( R n ) b Λ ˙ β , q ( R n ) c β , q b Λ ˙ β , 1 ( R n ) .

The works of Campanato and Meyers led to this equivalence ([33, p. 183] and [34, p. 718], where both authors showed that these norms are equivalent to the Lip θ norm). For an account of these facts, see [35, p. 72] and also [36, Theorem 3.1].

Definition 6

For a fixed cube Q 0 , the Hardy-Littlewood maximal function with respect to Q 0 of a function f is given by

M Q 0 f ( x ) sup Q 0 Q x 1 Q Q f ( y ) d y ,

where the supremum is taken over all the cubes Q with Q 0 Q and Q x .

The following characterization for nonnegative Lipschitz functions can be deduced from the proof of Theorem 1.4 in [37] [14, Lemma 2.2].

Lemma 1

[14, Lemma 2.2] Let b be a locally integrable function and β ( 0 , 1 ) . Then, the following statements are equivalent:

  1. b Λ ˙ β ( R n ) and b 0 .

  2. For all 1 s < ,

    (4) sup Q 1 Q β n 1 Q Q b ( x ) M Q ( b ) ( x ) s d x 1 s < .

  3. (4) holds for some 1 s < .

In the theory of partial differential equations (PDEs), Morrey spaces play an important role which was introduced by Morrey [38] in 1938 in connection with certain problems in elliptic PDEs and calculus of variations.

Definition 7

Let 1 p < , 0 λ n . We denote by L p , λ = L p , λ ( R n ) the Morrey space, and by W L p , λ = W L p , λ ( R n ) weak Morrey space, the sets of locally integrable functions f , with the finite norms

f L p , λ ( R n ) sup Q 1 Q λ n Q f ( y ) p d y 1 p < , f W L p , λ ( R n ) sup r > 0 r sup Q 1 Q λ n { y Q : f ( y ) > r } 1 p < ,

respectively.

Wang and Si [39] obtained the necessary and sufficient conditions on the parameters for the boundedness of the multilinear fractional maximal operator Ω , α and the multilinear fractional integral operator Ω , α with rough kernels on Morrey spaces.

Lemma 2

[39, Theorem 1.1]  0 < α < m n , 1 < s < , s = s ( s 1 ) , Ω ( S m n 1 ) . Suppose that λ p = j = 1 m λ j p j , 1 q j = 1 p j α m ( n λ j ) , and 0 λ j < n α p j m .

  1. p > s and λ q = j = 1 m λ j q j , then the condition 1 q = 1 p α n λ is necessary and sufficient condition for the boundedness of the operator Ω , α from L p 1 , λ 1 ( R n ) × × L p m , λ m ( R n ) to L q , λ ( R n ) .

  2. p = s and j = 1 m λ j p j q j = λ j = 1 m 1 p j q j , then the condition 1 q = 1 p α n λ is necessary and sufficient condition for the boundedness of the operator Ω , α from L p 1 , λ 1 ( R n ) × × L p m , λ m ( R n ) to W L q , λ ( R n ) .

When Ω 1 , Ω , α is the multilinear fractional maximal operator α defined in (2).

Remark 2

Lemma 2 also holds for s = . We leave the details to the reader.

3 Proof of Theorems 1 and 2

As we have mentioned in Section 1, we will prove Theorems 1 and 2.

Proof of the Theorem 1

(i) (ii) If b ( Λ ˙ β ) m , then for any x R n , we have

(5) α , b ( f ) ( x ) i = 1 m b i Λ ˙ β α + β ( f ) ( x ) .

Indeed,

(6) α , b i ( f ) ( x ) = sup Q x 1 Q m α n Q m b i ( x ) b i ( y i ) j = 1 m f j ( y j ) d y b i Λ ˙ β sup Q x 1 Q m ( α + β ) n Q m j = 1 m f j ( y j ) d y b i Λ ˙ β α + β ( f ) ( x ) .

Thus,

(7) α , b ( f ) ( x ) = i = 1 m α , b i ( f ) ( x ) i = 1 m b i Λ ˙ β α + β ( f ) ( x ) .

Then, using lattice property of the norm, inequality (7), and Lemma 2 (i), respectively, we obtain

α , b ( f ) L q , λ ( R n ) b Λ ˙ β α + β ( f ) L q , λ ( R n ) b Λ ˙ β j = 1 m f j L p j , λ j ( R n ) .

(ii) (i) We may assume j = 1 and m = 2 , without loss of generality, and α , b is bounded from L p 1 , λ 1 ( R n ) × L p 2 , λ 2 ( R n ) to L q , λ ( R n ) . Then, we obtain

1 Q 1 + β n Q b 1 ( x ) ( b 1 ) Q d x 1 Q 2 + β n Q Q b 1 ( x ) b 1 ( y ) d y 1 d x = 1 Q 1 + α + β n Q 1 Q 2 α n Q b 1 ( x ) b 1 ( y ) χ Q ( y 1 ) d y 1 Q χ Q ( y 2 ) d y 2 d x 1 Q 1 + α + β n Q α , b 1 ( χ Q , χ Q ) ( x ) d x 1 Q 1 + α + β n 1 Q λ n Q α , b 1 ( χ Q , χ Q ) q ( x ) d x 1 q Q λ n q + 1 q Q λ n q + 1 q 1 α + β n χ Q L p 1 , λ 1 ( R n ) χ Q L p 2 , λ 2 ( R n ) Q λ n q + 1 q 1 α + β n + 1 p 1 λ 1 n p 1 + 1 p 2 λ 2 n p 2 = c ,

which proves that b 1 Λ ˙ β ( R n ) . This completes the proof.□

Proof of the Theorem 2

(i) (ii) By using inequality (5), lattice property of the norm, and Lemma 2, respectively, we obtain

α , b ( f ) W L q , λ ( R n ) b Λ ˙ β α + β ( f ) W L q , λ ( R n ) b Λ ˙ β j = 1 m f j L p j , λ j ( R n ) .

(ii) (i) For any fixed cube Q 0 and any x Q 0 , we obtain

α , b i ( χ Q 0 ) ( x ) = sup Q x 1 Q m α n Q m b i ( x ) b i ( y i ) j = 1 m χ Q 0 ( y j ) d y 1 Q 0 m α n ( Q 0 ) m b i ( x ) b i ( y i ) j = 1 m χ Q 0 ( y j ) d y = 1 Q 0 1 α n Q 0 b i ( x ) b i ( y i ) χ Q 0 ( y i ) d y i Q 0 α n b i ( x ) ( b i ) Q 0

[30, p. 10]. Along with the definition of α , b gives

b i ( x ) ( b i ) Q 0 Q 0 α n α , b i ( χ Q 0 ) ( x ) Q 0 α n α , b ( χ Q 0 ) ( x ) .

Since α , b is bounded from L p 1 , λ 1 ( R n ) × × L p m , λ m ( R n ) to W L q , λ ( R n ) , we have

(8) { x Q 0 : b i ( x ) ( b i ) Q 0 > λ } { x Q 0 : Q 0 α n α , b ( χ Q 0 ) ( x ) > λ } Q 0 λ n λ 1 Q 0 α n j = 1 m χ Q 0 L p j , λ j ( R n ) q λ q Q 0 q ( λ n q λ n p + 1 p α n ) ,

where 1 p = 1 p 1 + + 1 p m .

Let t > 0 be a constant to be determined later. Then, by (8) and noting that q > 1 , we obtain

1 Q 0 1 + β n Q 0 b i ( x ) ( b i ) Q 0 d x = 1 Q 0 1 + β n 0 { x Q 0 : b i ( x ) ( b i ) Q 0 > u } d u = 1 Q 0 1 + β n 0 t + t { x Q 0 : b i ( x ) ( b i ) Q 0 > u } d u t Q 0 1 + β n Q 0 + 1 Q 0 1 + β n t u q Q 0 q ( λ n q λ n p + 1 p α n ) d u .

If we take t = Q 0 β n and note that 1 q = 1 p ( α + β ) ( n λ ) , we obtain

1 Q 0 1 + β n Q 0 b i ( x ) ( b i ) Q 0 d x 1 + Q 0 1 β n Q 0 q ( λ n q λ n p + 1 p α n ) Q 0 β n q β n c .

It follows from (3) that b i Λ ˙ β ( R n ) since Q 0 is arbitrary. The proof is completed.□

4 Proof of Theorems 3 and 4

To prove Theorems 3 and 4, we need some auxiliary definitions and lemmas. One of these is the pointwise estimate such that nonlinear commutator [ b , α ] can be controlled by maximal commutator α , b when b satisfies some suitable assumptions.

Lemma 3

[30, Lemma 4.1] Let 0 α < m n and b = ( b 1 , b 2 , , b m ) be a collection of nonnegative locally integrable functions. Then, for all f = ( f 1 , f 2 , , f m ) with locally integrable function f j , j = 1 , , m ,

[ b , α ] ( f ) ( x ) α , b ( f ) ( x ) .

Definition 8

Let 0 α < m n and f = ( f 1 , f 2 , , f m ) be a collection of locally integrable functions, the multi-sublinear maximal function with respect to Q is defined by

(9) α , Q ( f ) ( x ) = sup Q Q x j = 1 m 1 Q m α n Q f j ( y j ) d y j , x R n ,

where the supremum is taken over all the cubes Q such that Q Q x . When α = 0 , we simply write Q = 0 , Q .

Lemma 4

[30, Lemma 4.2] Let 0 α < m n , f be a locally integrable function, and Q 0 be a cube in R n . Then, for any 1 j m and all x Q 0 ,

(10) α , Q 0 ( χ Q 0 , , χ Q 0 j 1 , f χ Q 0 , χ Q 0 , , χ Q 0 m j ) ( x ) = α ( χ Q 0 , , χ Q 0 j 1 , f χ Q 0 , χ Q 0 , , χ Q 0 m j ) ( x )

and

(11) α , Q 0 ( χ Q 0 , , χ Q 0 m ) ( x ) = α ( χ Q 0 , , χ Q 0 m ) ( x ) = Q 0 α n .

Lemma 5

Let 0 < β < 1 , 0 α < m n , 0 < α + β < m n , and b = ( b 1 , b 2 , , b m ) be a collection of locally integrable function. Suppose that 1 < p 1 , , p m < , 1 p = 1 p 1 + + 1 p m , q > 1 , λ p = i = 1 m λ i p i , 1 q i = 1 p i α + β m ( n λ i ) , 0 λ i < n ( α + β ) p i m , and 1 q = 1 p α + β n λ . If [ b , α ] i is bounded from L p 1 , λ 1 ( R n ) × × L p m , λ m ( R n ) to L q , λ ( R n ) , then

sup Q Q β n 1 Q Q b i ( x ) Q α n α , Q ( b i χ Q i ) ( x ) q d x 1 q < ,

where ( b i χ Q i ) = ( χ Q , , χ Q i 1 , b i χ Q , χ Q , , χ Q m i ) as above.

Proof

For any fixed cube Q and all x Q , the following equalities are valid:

α ( b i χ Q i ) ( x ) = α , Q ( b i χ Q i ) ( x ) , α ( χ Q ) ( x ) = Q α n

[30, p. 14]. Since [ b , α ] i is bounded from L p 1 , λ 1 ( R n ) × × L p m , λ m ( R n ) to L q , λ ( R n ) and note that 1 q = 1 p ( α + β ) ( n λ ) , then

Q β n 1 Q Q b i ( x ) Q α n α , Q ( b i χ Q i ) ( x ) q d x 1 q = Q 1 q α + β n Q b i ( x ) Q α n α , Q ( b i χ Q i ) ( x ) q d x 1 q = Q 1 q α + β n Q b i ( x ) α ( χ Q ) ( x ) α ( b i χ Q i ) ( x ) q d x 1 q = Q 1 q α + β n Q [ b , α ] i ( χ Q ) ( x ) q d x 1 q = Q 1 q α + β n λ n q 1 Q λ n R n [ b , α ] i ( χ Q ) ( x ) q d x 1 q Q 1 q α + β n λ n q [ b , α ] i ( χ Q ) ( x ) L q , λ ( R n ) Q 1 q α + β n λ n q i = 1 m ( χ Q ) L p i , λ i ( R n ) Q 1 q α + β n λ n q + n λ n p c .

By taking the supremum of both sides because the constant c is independent of f , we are done.□

Lemma 6

[30, Lemma 4.4] Let 0 < β < 1 , 0 α < m n , 0 < α + β < m n , and 1 s < . If f is a locally integrable function and satisfies, for some 1 i m ,

sup Q Q β n 1 Q Q f ( x ) Q α n α , Q ( f χ Q i ) ( x ) s d x 1 s < ,

then f Λ ˙ β ( R n ) , where ( f χ Q i ) = ( χ Q , , χ Q i 1 , f χ Q , χ Q , , χ Q m i ) as above.

Proof of the Theorem 3

The first part of the theorem is obvious from Lemma 3, (7), and Lemma 2 (i). The second part will be proven. By the hypothesis,

(12) [ b , α ] i ( f ) L q , λ ( R n ) c i = 1 m f i L p i , λ i ( R n )

holds for the constant c independent of f . By Lemma 1, it suffices to prove that

(13) sup Q Q β n 1 Q Q b i ( x ) M Q ( b i ) ( x ) d x < .

Case 1. Let α = 0 . Then, from [30, Lemma 4.2], for any fixed cube Q and any x Q , we obtain

( b i χ Q i ) ( x ) = Q ( b i χ Q i ) ( x ) = M Q ( b i ) ( x ) , ( χ Q ) ( x ) = 1 ,

where χ Q = ( χ Q , , χ Q m ) and ( f χ Q i ) = ( χ Q , , χ Q i 1 , f χ Q , χ Q , , χ Q m i ) as above.

Since 1 q = 1 p 1 + + 1 p m ( α + β ) ( n λ ) in this case, it follows from (12) that

Q β n 1 Q Q b i ( x ) M Q ( b i ) ( x ) d x = Q β n 1 Q Q b i ( x ) ( χ Q ) ( x ) ( b i χ Q i ) ( x ) d x = Q β n 1 Q Q [ b , ] i ( χ Q ) ( x ) d x Q β n 1 Q Q [ b , ] i ( χ Q ) ( x ) q d x 1 q Q β n 1 q + λ n q Q λ n n p = c

which implies (13), since Q is arbitrary cube in R n and the constant c is independent of f .

Case 2. Let 0 < α < m n . For any fixed cube Q , we have

(14) Q β n 1 Q Q b i ( x ) M Q ( b i ) ( x ) d x Q β n 1 Q Q b i ( x ) Q α n α , Q ( b i χ Q i ) ( x ) d x + Q β n 1 Q Q Q α n α , Q ( b i χ Q i ) ( x ) M Q ( b i ) ( x ) d x I 1 + I 2 .

For I 1 , since [ b , α ] i is bounded from L p 1 , λ 1 ( R n ) × × L p m , λ m ( R n ) to L q , λ ( R n ) , it follows from Hölder’s inequality and Lemma 5 that

(15) I 1 Q β n 1 Q Q b i ( x ) Q α n α , Q ( b i χ Q i ) ( x ) q d x 1 q c .

Next we consider I 2 . For all x Q , by Lemma 4, we obtain

Q α n α , Q ( b i χ Q i ) ( x ) M Q ( b i ) ( x ) Q α n α , Q ( b i χ Q i ) ( x ) b i ( x ) Q α n + b i ( x ) M Q ( b i ) ( x ) = Q α n α ( b i χ Q i ) ( x ) b i ( x ) α ( χ Q ) ( x ) + b i ( x ) ( χ Q ) ( x ) ( b i χ Q i ) ( x ) = Q α n [ b i , α ] i ( χ Q ) ( x ) + [ b i , ] i ( χ Q ) ( x ) .

Then,

I 2 = Q β n 1 Q Q Q α n α , Q ( b i χ Q i ) ( x ) M Q ( b i ) ( x ) d x Q 1 q α + β n Q [ b i , α ] i ( χ Q ) ( x ) q d x 1 q + Q 1 q β n Q [ b i , ] i ( χ Q ) ( x ) q d x 1 q c

because of the fact that [ b , α ] i is bounded from L p 1 , λ 1 ( R n ) × × L p m , λ m ( R n ) to L q , λ ( R n ) , then it follows from Lemmas 5 and 6, b i Λ ˙ β ( R n ) which implies b i Λ ˙ β ( R n ) . Thus, we can apply Lemma 3 for each j entry and (6) to [ b i , α ] i and [ b i , ] i , since b i Λ ˙ β ( R n ) and b i 0 . Then, by (11), we have

[ b i , α ] i ( χ Q ) ( x ) α + β ( χ Q ) ( x ) = c Q α + β n

and

[ b i , ] i ( χ Q ) ( x ) β ( χ Q ) ( x ) = c Q β n .

Therefore I 2 c . This along with (14) and (15) gives

Q β n 1 Q Q b i ( x ) M Q ( b i ) ( x ) d x c ,

which implies b i Λ ˙ β ( R n ) and b i 0 by Lemma 1. The proof of Theorem 3 is completed.□

Proof of the Theorem 4

b ( Λ ˙ β ) m and b i 0 for i = 1 , 2 , , m , then by Lemma 3 and (7), we have

[ b , α ] ( f ) ( x ) α , b ( f ) ( x ) b ( Λ ˙ β ) m α + β ( f ) ( x ) .

Obviously, Theorem 4 can be obtained from Lemma 2 (ii).□

Acknowledgements

The authors would like to thank the referees for their very helpful and detailed comments.

  1. Funding information: Pu Zhang was supported by the Fundamental Research Funds for Education Department of Heilongjiang Province (No. 1453ZD031).

  2. Author contributions: All authors contributed equally to this work. All authors read and approved the final manuscript.

  3. Conflict of interest: The authors state no conflict of interest.

  4. Data availability statement: No data were used to support this study.

References

[1] R. R. Coifman, R. Rochberg, and G. Weiss, Factorization theorems for Hardy spaces in several variables, Ann. of Math. 103 (1976), no. 3, 611–635, DOI: https://doi.org/10.2307/1970954. 10.2307/1970954Search in Google Scholar

[2] S. Janson, Mean oscillation and commutators of singular integral operators, Ark. Mat. 16 (1978), no. 2, 263–270, DOI: https://doi.org/10.1007/BF02386000. 10.1007/BF02386000Search in Google Scholar

[3] M. Paluszyński, Characterization of the Besov spaces via the commutator operator of Coifman, Rochberg and Weiss, Indiana Univ. Math. J. 44 (1995), no. 1, 1–17, DOI: http://www.jstor.org/stable/24898462. 10.1512/iumj.1995.44.1976Search in Google Scholar

[4] J. Garciiia-Cuerva, E. Harboure, C. Segovia, and J. L. Torrea, Weighted norm inequalities for commutators of strongly singular integrals, Indiana Univ. Math. J. 40 (1991), no. 4, 1397–1420, DOI: https://www.jstor.org/stable/24896301. 10.1512/iumj.1991.40.40063Search in Google Scholar

[5] C. Segovia and J. L. Torrea. Vector-valued commutators and applications, Indiana Univ. Math. J. 38 (1989), no. 4, 959–971, DOI: http://www.jstor.org/stable/24895375. 10.1512/iumj.1989.38.38044Search in Google Scholar

[6] C. Segovia and J. L. Torrea, Weighted inequalities for commutators of fractional and singular integrals, Conference on Mathematical Analysis (El Escorial, 1989), Publ. Mat. 35 (1991), no. 1, 209–235.10.5565/PUBLMAT_35191_09Search in Google Scholar

[7] Y. Ding, S. Lu, and P. Zhang, Weak estimates for commutators of fractional integral operators, Sci. China Ser. A. 44 (2001), no. 7, 877–888, DOI: https://doi.org/10.1007/BF02880137. 10.1007/BF02880137Search in Google Scholar

[8] A. Almeida, Maximal commutators and commutators of potential operators in new vanishing Morrey spaces, Nonlinear Anal. 192, (2020), 111684, DOI: https://doi.org/10.1016/j.na.2019.111684. 10.1016/j.na.2019.111684Search in Google Scholar

[9] V. S. Guliyev, F. Deringoz, and S. G. Hasanov, Commutators of fractional maximal operator on Orlicz spaces, Math. Notes 104 (2018), no. 4, 498–507, DOI: https://doi.org/10.1134/S0001434618090171. 10.1134/S0001434618090171Search in Google Scholar

[10] V. S. Guliyev and P. S. Shukurov, On the boundedness of the fractional maximal operator, Riesz potential and their commutators in generalized Morrey spaces, in: A. Almeida, L. Castro, F.O. Speck (Eds.), Advances in Harmonic Analysis and Operator Theory, Operator Theory: Advances and Applications, vol. 229. Birkhäuser, Basel, 2013, pp. 175–199, DOI: https://doi.org/10.1007/978-3-0348-0516-2_10. 10.1007/978-3-0348-0516-2_10Search in Google Scholar

[11] M. Milman and T. Schonbek, Second order estimates in interpolation theory and applications, Proc. Amer. Math. Soc. 110 (1990), no. 4, 961–969, DOI: https://doi.org/10.1090/S0002-9939-1990-1075187-4. 10.1090/S0002-9939-1990-1075187-4Search in Google Scholar

[12] P. Zhang and J. Wu, Commutators of fractional maximal functions, Acta Math. Sinica (Chinese Ser.) 52 (2009), no. 6, 1235–1238. Search in Google Scholar

[13] P. Zhang and J. Wu, Commutators of fractional maximal functions on variable exponent Lebesgue spaces, Czechoslovak Math. J. 64 (2014), no. 1, 183–197, DOI: https://doi.org/10.1007/s10587-014-0093-x. 10.1007/s10587-014-0093-xSearch in Google Scholar

[14] P. Zhang, Z. Si, and J. Wu, Some notes on commutators of the fractional maximal function on variable Lebesgue spaces, J. Inequal. Appl. 2019 (2019), 9, DOI: https://doi.org/10.1186/s13660-019-1960-7. 10.1186/s13660-019-1960-7Search in Google Scholar

[15] V. S. Guliyev, F. Deringoz, and S. G. Hasanov, Fractional maximal function and its commutators on Orlicz spaces, Anal. Math. Phys. 9 (2019), no. 1, 165–179, DOI: https://doi.org/10.1007/s13324-017-0189-1. 10.1007/s13324-017-0189-1Search in Google Scholar

[16] P. Zhang, J. Wu, and J. Sun, Commutators of some maximal functions with Lipschitz function on Orlicz spaces, Mediterr. J. Math. 15 (2018), 216, DOI: https://doi.org/10.1007/s00009-018-1263-0. 10.1007/s00009-018-1263-0Search in Google Scholar

[17] R. R. Coifman and Y. Meyer, On commutators of singular integrals and bilinear singular integrals, Trans. Amer. Math. Soc. 212 (1975), 315–331, DOI: https://doi.org/10.1090/S0002-9947-1975-0380244-8. 10.2307/1998628Search in Google Scholar

[18] L. Grafakos and R. Torres, Multilinear Calderón-Zygmund theory, Adv. Math. 165 (2002), no. 1, 124–164, DOI: https://doi.org/10.1006/aima.2001.2028. 10.1006/aima.2001.2028Search in Google Scholar

[19] W. Damián, A. Lerner, and C. Pérez, Sharp weighted bounds for multilinear maximal functions and Calderón-Zygmund operators, J. Fourier Anal. Appl. 21 (2015), no. 1, 161–181, DOI: https://doi.org/10.1007/s00041-014-9364-z. 10.1007/s00041-014-9364-zSearch in Google Scholar

[20] A. Lerner, S. Ombrosi, C. Pérez, R. Torres, and R. Trujillo-González, New maximal functions and multiple weights for the multilinear Calderón-Zygmund theory, Adv. Math. 220 (2009), no. 4, 1222–1264, DOI: https://doi.org/10.1016/j.aim.2008.10.014. 10.1016/j.aim.2008.10.014Search in Google Scholar

[21] G. Lu and P. Zhang, Multilinear Calderón-Zygmund operators with kernels of Dini’s type and applications, Nonlinear Anal. 107 (2014), 92–117, DOI: https://doi.org/10.1016/j.na.2014.05.005. 10.1016/j.na.2014.05.005Search in Google Scholar

[22] K. Moen, Weighted inequalities for multilinear fractional integral operators, Collect. Math. 60 (2009), no. 2, 213–238, DOI: https://doi.org/10.1007/BF03191210. 10.1007/BF03191210Search in Google Scholar

[23] C. Pérez and R. Torres, Sharp maximal function estimates for multilinear singular integrals, Contemp. Math. 320 (2003), 323–331, DOI: https://doi.org/10.1090/conm/320. 10.1090/conm/320/05615Search in Google Scholar

[24] C. Pérez, G. Pradolini, R. Torres, and R. Trujillo-González, End-point estimates for iterated commutators of multilinear singular integrals, Bull. Lond. Math. Soc. 46 (2014), no. 1, 26–42, DOI: https://doi.org/10.1112/blms/bdt065. 10.1112/blms/bdt065Search in Google Scholar

[25] C. Pérez and R. Trujillo-González, Sharp weighted estimates for multilinear commutators, J. Lond. Math. Soc. 65 (2002), no. 3, 672–692, DOI: https://doi.org/10.1112/S0024610702003174. 10.1112/S0024610702003174Search in Google Scholar

[26] X. Chen and Q. Xue, Weighted estimates for a class of multilinear fractional type operators, J. Math. Anal. Appl. 362 (2010), no. 2, 355–373, DOI: https://doi.org/10.1016/j.jmaa.2009.08.022. 10.1016/j.jmaa.2009.08.022Search in Google Scholar

[27] P. Zhang, Multiple weighted estimates for commutators of multilinear maximal function, Acta Math. Sin. (Engl. Ser.) 31 (2015), no. 6, 973–994, DOI: https://doi.org/10.1007/s10114-015-4293-6. 10.1007/s10114-015-4293-6Search in Google Scholar

[28] D. Wang and G. Wang, Necessary and sufficient conditions for boundedness of commutators of bilinear Hardy-Littlewood maximal function, Math. Inequal. Appl. 25 (2022), no. 3, 789–807, DOI: https://doi.org/10.7153/mia-2022-25-50. 10.7153/mia-2022-25-50Search in Google Scholar

[29] X. Yu, P. Zhang, and H. Li, Some estimates for the commutators of multilinear maximal function on Morrey-type space, Open Math. 19 (2021), no. 1, 515–530, DOI: https://doi.org/10.1515/math-2021-0031. 10.1515/math-2021-0031Search in Google Scholar

[30] P. Zhang, Commutators of multi-sublinear maximal functions with Lipschitz functions, Results Math. 74 (2019), 49, DOI: https://doi.org/10.1007/s00025-019-0971-5. 10.1007/s00025-019-0971-5Search in Google Scholar

[31] R. A. DeVore and R. C. Sharpley, Maximal functions measuring smoothness, Memoirs of the American Mathematical Society, vol. 293, American Mathematical Society (AMS), Providence, RI, 1984. 10.1090/memo/0293Search in Google Scholar

[32] S. Janson, M. Taibleson, and G. Weiss, Elementary characterizations of the Morrey-Campanato spaces, Harmonic analysis, Proceedings of a Conference, Cortona/Italy 1982, Lecture Notes on Mathematics, vol. 992, 1983, DOI: https://doi.org/10.1007/BFb0069154. 10.1007/BFb0069154Search in Google Scholar

[33] S. Campanato, Proprieta di Hölderianita di alcune classi di funzioni, Ann. Sc. Norm. Super. Pisa Cl. Sci. (3) 17 (1963), no. 1–2, 175–188, http://www.numdam.org/item/ASNSP_1963_3_17_1-2_175_0/. Search in Google Scholar

[34] N. G. Meyers, Mean oscillation over cubes and Hölder continuity, Proc. Amer. Math. Soc. 15 (1964), no. 5, 717–721, DOI: https://doi.org/10.2307/2034586. 10.1090/S0002-9939-1964-0168712-3Search in Google Scholar

[35] J. Peetre, On the theory of ℒp,λ spaces, J. Funct. Anal. 4 (1969), no. 1, 71–87, DOI: https://doi.org/10.1016/0022-1236(69)90022-6. 10.1016/0022-1236(69)90022-6Search in Google Scholar

[36] E. Nakai, A generalization of Hardy spaces Hp by using atoms, Acta Math. Sin. (Engl. Ser.) 24 (2008), no. 8, 1243–1268, DOI: https://doi.org/10.1007/s10114-008-7626-x. 10.1007/s10114-008-7626-xSearch in Google Scholar

[37] P. Zhang, Characterization of Lipschitz spaces via commutators of the Hardy-Littlewood maximal function, C. R. Math. Acad. Sci. Paris 355 (2017), no. 3, 336–344, DOI: https://doi.org/10.1016/j.crma.2017.01.022. 10.1016/j.crma.2017.01.022Search in Google Scholar

[38] C. B. Morrey, On the solutions of quasi-linear elliptic partial differential equations, Trans. Amer. Math. Soc. 43 (1938), no. 1, 126–166, DOI: https://doi.org/10.1090/S0002-9947-1938-1501936-8. 10.1090/S0002-9947-1938-1501936-8Search in Google Scholar

[39] Z. Wang and Z. Si, Necessary and sufficient conditions for the boundedness of rough multilinear fractional operators on Morrey-type spaces, J. Inequal. Appl. 2015 (2015), 104, DOI: https://doi.org/10.1186/s13660-015-0627-2. 10.1186/s13660-015-0627-2Search in Google Scholar

Received: 2024-05-25
Revised: 2024-09-10
Accepted: 2024-09-11
Published Online: 2024-10-15

© 2024 the author(s), published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 International License.

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