Abstract
In this paper, we study the boundedness of rough Maximal integral operators along surfaces of revolution on product domains. For several classes of surfaces, we establish appropriate bounds of these Maximal operators under the assumption for some , and then we employ these bounds along with Yano’s extrapolation argument to obtain the boundedness of the aforementioned integral operators under a weaker condition in which belongs to either the space or to the space . Our results extend and improve many previously known results.
MSC:
42B20; 42B25
1. Introduction
Let ( or ) be the s-dimensional Euclidean space and be the unit sphere in equipped with the normalized Lebesgue surface measure .
Let be a function defined on with the following properties:
Let () be the class of all radial functions such that
For an appropriate mapping , we define the maximal operator along the surface of revolution given by
where and
When and , we denote by . In this case, the operator is just the classical maximal integral operator on product domains, which was proven to be bounded on provided that (see [1]). Thereafter, the study of the boundedness of has attracted the attention of many authors. Let us recall some known results relevant to our current study. In [2], the author improved and extended the result in [1]. In fact, he proved the boundedness of for all under the condition and the condition that is the best possible in the sense that the space cannot be replaced by a larger space for any . On the other hand, if lies in the space with , the author of [3] proved the boundedness of for all and the condition is the best possible in the sense that it cannot be replaced by any weaker condition with . Subsequently, the investigation of the boundedness of and some of its extensions has attracted the attention of many authors in the last two decades. For more results we advice the readers to refer to [4,5], and the references therein. For the importance of studying the integral operators with oscillating kernels, the readers are advised to consult [6,7,8,9,10,11,12,13,14,15].
We point out our maximal operator is an extension of the maximal operator (in the one parameter setting) given by
where ,
and is homogeneous function of degree zero, integrable over and satisfies the cancellation condition
The maximal operator and its extensions has attracted the attention of many authors, see for example [16,17,18,19,20,21,22,23,24].
We remark that recently, the authors of [25] studied the boundedness of the singular integral operators under various conditions on , and h. Indeed, they established the boundedness of whenever belongs to either or to .
In light of the results in [18,20] concerning the boundedness of the maximal integral in the one-parameter setting and the results in [25] concerning the boundedness of in the product spaces, a question arises naturally as follows:
- Question: Under the assumptions imposed on in [25], does the operator satisfy the boundedness if and with ?
The purpose of this work is to answer this question in the affirmative. In fact, we have the following:
Theorem 1.
Let such that for any fixed , we have , are in , convex and increasing functions with . Assume that and for some . Then, there exists a constant such that
for all if , and
Theorem 2.
Theorem 3.
Theorem 4.
By the estimates obtained in Theorems 1–4 and employing an extrapolation argument (see [26,27]) we get the following results.
Theorem 5.
for all with ;
for all with .
Let Ψ be given as in any of Theorems 1–4, Ω satisfy the conditions (1) and (2) and .
- (i)
- If for some , then we have
- (ii)
- If , then we have
By using the estimates in Theorem 5, employing the fact that
and using a standard duality argument, we directly get the following:
Theorem 6.
Suppose that Ψ is given as in Theorem 5. Let with and with . Then the operator is bounded on for all .
Remark 1.
For the special cases and , the conditions on Ω in Theorem 5 are the weakest possible conditions among their respective classes, (see [2,3]).
Remark 2.
For the special cases and , the author of [1] showed that is bounded on provided that . This result is improved in Theorem 5 since .
Remark 3.
For the case , it was proved in [25] that is bounded on for all provided that . Hence, the results in Theorem 6 improve the results in [25] whenever with .
Remark 4.
In Theorem 6, we proved the boundedness of the operator for all , which is the full range for p.
Remark 5.
The surfaces of revolutions considered in this paper cover various natural classical surfaces such as those in [28,29,30,31,32,33,34]. For instance, our main results allow surfaces of the type with ; with ; , where each is a convex increasing function with ; is a polynomial.
Henceforward, the constant C denotes a positive real constant which may not necessarily be the same at each occurrence, but it is independent of all the essential variables.
2. Preliminary Lemmas
In this section, we introduce some notations and establish some lemmas. The class (for denotes the class of all measurable functions on which satisfy
Now we recall the definition of the class of . A q-block on is an function that satisfies and , where denotes the product measure on and I is an interval on i.e.,
for some , and The block space is defined by
where each is a complex number, each is a q-block supported on an interval on , and
Let : and each is a q-block function supported on a cap on .
We remark here that for any and the following inclusions hold and are proper:
The question concerning the relationship between the spaces and (for remains open.
For , an arbitrary mapping on and , we consider the family of measures and its related maximal operator on by
and
where is defined similarly to but with replacing by .
Lemma 1.
Suppose that and for some satisfies the conditions (1) and (2). For , and , let
Then we have
where and .
Proof.
By Schwartz inequality, we get
where and . Hence, by Van der Corput’s lemma we deduce that
where . By combining the last estimate with the trivial estimate , we obtain that
for any . Thus, by Hölder’s inequality, we have that
Choosing small enough such that gives that the last integral is finite. Therefore,
In the same manner, we derive that
On the other side, the cancellation condition (2) gives that
which when combined with the trivial estimate imply
Similarly, we acquire that
Consequently, by combining the inequalities (7)–(10), the estimate (5) is satisfied. The proof of this lemma is complete. □
We need the following lemma from [25] which will play a key role in proving our main results.
3. Proof of the Main Results
Let be given as in any of Theorems 1–4, with and for some . By duality, we get
where
To prove our the main results, we consider three cases:
Case 1. . Let be a set of smooth partition of unity defined on , and adapted to the interval . Precisely, we have the following:
where the constant does not depend on the lacunary sequence . For , let be the multiplier operators defined on by
So, for any and , we have
By invoking Minkowski’s inequality, it is easy to see that
where
and
Therefore, to prove our results, it is enough to show that the estimate
holds for all for some .
First, the -norm for can be obtained by employing Plancherel’s Theorem and Fubini’s Theorem together with Lemma 1. Precisely, we have
where and .
Next, the -norm of is estimated as follows: by duality, there is a non-negative function such that and
where . Hence, by Lemma 2 and Littlewood–Paley theory (see [35]), we get
for all . Therefore, by interpolating (16) with (18), we obtain (15). Therefore, use (14) and take , we directly obtain that
for all .
Case 2. . In this case, we have . Hence,
for every . Thus, when we take the supremum to the both sides of the last inequality over all radial functions h with , we get
for almost every . Therefore,
4. Conclusions
In this article, we obtained sharp bounds for several classes of Maximal integral operators related to surfaces of revolution on product spaces whenever and for some , . By the virtue of these bounds and the extrapolation argument of Yano, we proved that the operator is bounded on provided that . In addition, under specific assumptions, we confirmed the boundedness of for the full range of . Further, the boundedness of the aforesaid operator is proven when the conditions on are the weakest possible conditions among their respective classes. The results in this article extend or improve many known results on maximal operators as the results in [1,2,3,25].
Author Contributions
Formal analysis and writing—original draft preparation: M.A. and H.A.-Q. All authors have read and agreed to the published version of the manuscript.
Funding
This research received no external funding.
Data Availability Statement
No data were used to support this study.
Acknowledgments
The authors would like to express their gratitude to the referees for their valuable comments and suggestions in improving writing this paper. In addition, they are grateful to the editor for handling the full submission of the manuscript.
Conflicts of Interest
The authors declare that they have no conflict of interest.
References
- Ding, Y. A note on a class of rough maximal operators on product domains. J. Math. Anal. Appl. 1999, 232, 222–228. [Google Scholar] [CrossRef][Green Version]
- Al-Salman, A. Maximal operators with rough kernels on product domains. J. Math. Anal. Appl. 2005, 311, 338–351. [Google Scholar] [CrossRef][Green Version]
- Al-Qassem, H. Lp estimates for a rough maximal operator on product spaces. J. Korean Math. Soc. 2005, 42, 405–434. [Google Scholar] [CrossRef]
- Xu, H.; Fan, D.; Wang, M. Some maximal operators related to families of singular integral operators. Acta. Math. Sin. 2004, 20, 441–452. [Google Scholar] [CrossRef]
- Al-Qassem, H.; Cheng, L.; Pan, P. On the boundedness of a class of rough maximal operators on product spaces. Hokkaido Math. J. 2011, 40, 1–32. [Google Scholar] [CrossRef]
- Fan, D.; Pan, Y. Boundedness of certain oscillatory singular integrals. Studia Math. 1995, 114, 105–116. [Google Scholar] [CrossRef]
- Kim, W.; Wainger, S.; Wright, J.; Ziesler, S. Singular Integrals and Maximal Functions Associated to Surfaces of Revolution. Bull. Lond. Math. Soc. 1996, 28, 291–296. [Google Scholar] [CrossRef]
- Jiang, Y.; Lu, S. Oscillatory singular integrals with rough kernel. In Harmonic Analysis in China; Cheng, M.D., Deng, D.G., Gong, S., Yang, C.-C., Eds.; Kluwer Academic: Dordrecht, The Netherlands, 1995; Volume 327, pp. 135–145. [Google Scholar]
- Stein, E. On the functions of Littlewood-Paley, Lusin and Marcinkiewicz. Trans. Am. Math. Soc. 1958, 88, 430–466. [Google Scholar] [CrossRef]
- Stein, E. Problems in harmonic analysis related to curvature and oscillatory integrals. Proc. Internat. Congr. Math. 1986, 1, 196–221. [Google Scholar]
- Stein, E. Some geometrical concepts arising in harmonic analysis. Geom. Funct. Anal. 2000, 434–453. [Google Scholar] [CrossRef]
- Lu, S.; Zhang, Y. Criterion on Lp-boundedness for a class of oscillatory singular integrals with rough kernels. Rev. Mat. Iber. 1992, 8, 201–219. [Google Scholar]
- Pan, P. L2 estimates for convolution operators with oscillating kernels. Math. Proc. Camb. Phil. Soc. 1993, 113, 179–193. [Google Scholar] [CrossRef]
- Ricci, F.; Stein, E. Harmonic analysis on nilpotent groups and singular integrals. I. Oscillatory integrals. J. Func. Anal. 1987, 73, 179–194. [Google Scholar] [CrossRef]
- Sjolin, P. Convolution with oscillating kernels. Indiana Univ. Math. J. 1981, 30, 47–55. [Google Scholar] [CrossRef]
- Chen, L.; Lin, H. A maximal operator related to a class of singular integral. Illinois J. Math. 1990, 34, 120–126. [Google Scholar] [CrossRef]
- Al-Salman, A. On maximal functions with rough kernels in L(logL)1/2(Sn-1). Collec. Math. 2005, 56, 47–56. [Google Scholar]
- Al-Qassem, H. On the boundedness of maximal operators and singular operators with kernels in L(logL)α(Sm-1). J. Ineq. Apll. 2006, 1, 1–16. [Google Scholar]
- Jiang, Y.; Lu, S. A class of singular integral operators with rough kernel on product domains. Hokkaido Math. J. 1995, 24, 1–7. [Google Scholar] [CrossRef]
- Al-Qassem, H.; Pan, Y. Singular integrals along surfaces of revolution with rough kernels. SUT J. Math. 2003, 39, 55–70. [Google Scholar] [CrossRef]
- Ding, Y.; He, Q. Weighted boundedness of a rough maximal operator. Acta Math. Sci. (Engl. Ed.) 2000, 20, 417–422. [Google Scholar] [CrossRef]
- Le, H. Maximal operators and singular integral operators along submanifolds. J. Math. Anal. Appl. 2004, 296, 44–64. [Google Scholar] [CrossRef]
- Duoandikoetxea, J.; Rubio de Francia, J. Maximal and singular integral operators via Fourier transform estimates. Invent Math. 1986, 84, 541–561. [Google Scholar] [CrossRef]
- Ali, M.; Al-Mohammed, O. Boundedness of a class of rough maximal functions. J. Ineq. Appl. 2018, 2018, 305. [Google Scholar] [CrossRef] [PubMed]
- Al-Qassem, H.; Cheng, L.; Pan, Y. On singular integrals and maximal operators along surfaces of revolution on product domains. J. Math. Ineq. 2023, 17, 739–759. [Google Scholar] [CrossRef]
- Yano, S. Notes on Fourier analysis. XXIX. An extrapolation theorem. J. Math. Soc. Jpn. 1951, 3, 296–305. [Google Scholar] [CrossRef]
- Sato, S. Estimates for singular integrals and extrapolation. Studia Math. 2009, 192, 219–233. [Google Scholar] [CrossRef]
- Carbery, A.; Wainger, S.; Wright, J. Double Hilbert transforms along polynomial surfaces in R3. Duke Math. J. 2000, 101, 499–513. [Google Scholar] [CrossRef]
- Carlsson, H.; Sjōgren, P. Estimates for maximal functions along hypersurfaces. Ark. Math. 1987, 25, 1–14. [Google Scholar] [CrossRef]
- Carlsson, H.; Sjōgren, P.; Stromberg, J. Multiparameter maximal functions along dilationinvariant hypersurfaces. Trans. Am. Math. Soc. 1985, 292, 335–343. [Google Scholar] [CrossRef]
- Duoandikoetxea, J. Multiple singular integrals and maximal functions along hypersurfaces. Ann. Ins. Four. 1986, 36, 185–206. [Google Scholar] [CrossRef]
- Fan, D.; Guo, K.; Pan, Y. Singular integrals with rough kernels on product spaces. Hokkaido Math. J. 1999, 28, 435–460. [Google Scholar] [CrossRef]
- Le, H. A note on singular integrals with dominating mixed smoothness in Triebel-Lizorkinspaces. Acta Math. Scientia. 2014, 34, 1331–1344. [Google Scholar] [CrossRef]
- Patel, S. Double Hilbert Transforms along Polynomial Surfaces in R3. Glasgow Math. J. 2008, 50, 395–428. [Google Scholar] [CrossRef][Green Version]
- Stein, E. Singular Integrals and Differentiability Properties of Functions; Princeton University Press: Princeton, NJ, USA, 1970. [Google Scholar]
- Benedek, A.; Panzone, R. The spaces Lp with mixed norm. Duke Math. J. 1961, 28, 301–324. [Google Scholar] [CrossRef]
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content. |
© 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).