1. Introduction
Throughout this article, we assume that ( or n) and is the Euclidean space of dimension . Also, we assume that is the unit sphere in equipped with the normalized Lebesgue surface measure .
For
, we let
where
h is a measurable function defined on
and
is a measurable function defined on
, integrable over
and satisfies the following:
For a suitable mapping
, the parametric Marcinkiewicz integral operator
along the surface of revolution
is defined, initially for
, by
where
We remark that the Marcinkiewicz operator is a natural generalization of the Marcinkiewicz operator
along surface of revolution
in the one parameter setting which is given by
The study of the
boundedeness of the operator
under various conditions on
and
has attracted the attention of many authors. For a sample of known results relevant to our study, the readers are referred to consult [
1,
2,
3,
4,
5].
Our main focus in this paper is the operator
. When
and
, we denote the operator
by
. In addition, when
, then
reduces to the classical Marcinkiewicz integral on product domains, which is denoted by
. The investigation of the
boundedness of the operator
initiated in [
6] in which the author proved the
boundedness of
under the condition
. Subsequently, the
boundedness of
has attracted the attention of many authors. For instance, in [
7] the authors proved the
(
) boundedness of
if
. In addition, they pointed out that by adapting a similar argument as that used in [
8] to the product space setting, the assumption
is optimal in the sense that if we replace it by any weaker condition
with
, then
may lose the
boundedness. On the other hand, under the assumption
belongs to
with
, it was proved in [
9] that
is of type
for all
and that the condition
is optimal in the sense that we cannot replace it by
with
so that
is bounded on
. Here
is a special class of block spaces introduced in [
10]. Later on, the authors of [
11] employed Yano’s extrapolation technique found in [
12] to establish the
boundedness of
for all
provided that
belongs to either
or to
and
for some
, where here
(for
) denotes the collection of measurable functions
h such that
For a sample of past studies as well as more information about the applications and development of the operator
, we refer the readers to see [
7,
9,
13,
14,
15,
16,
17,
18] and the references therein.
By the work done in these cited papers, many mathematicians have been motivated to study Marcinkiewicz operator along surfaces of revolution on product spaces of the form
where
The
boundedness of the operator
under different conditions on the functions
,
,
, and
h was discussed by many authors (one can consult [
15,
19,
20].
Very recently, in [
21] the authors studied the
boundedness of the singular integral operators
along surfaces of revolution on product domains which is defined by
where
is a suitable mapping. Under various conditions on
, the authors proved the
boundedness of
if
belongs to either
or to
.
In light of the results in [
20] regarding the boundedness of Marcinkiewicz operator
and of the results in [
21] regarding the boundedness of singular integral
, a question arises naturally is the following:
Question: Under the same conditions as those imposed on
in [
21], is the operator
bounded whenever
for some
and
lies in either the space
or in the space
with
?
In this article, we shall answer this question in affirmative. Indeed, we have the following:
Theorem 1.
Let such that for any fixed , we have , are in , increasing and convex functions with . Suppose that for some and for some . Then there is a constant such that
for all .
Theorem 2.
Let Ω and h be given as in Theorem 1. Suppose that with is a generalized polynomial on . Then there is a constant such that
for all .
Theorem 3.
Let Ω and h be given as in Theorem 1. Suppose that , where is in , increasing and convex function with and P is a generalized polynomials given by with . Then there is a constant such that
for all .
Theorem 4.
Let Ω and h be given as in Theorem 1. Suppose that , where () is either a generalized polynomial or is in , increasing and convex function with . Then there is a constant such that
for all .
By the conclusions from Theorems 1-4 along with the extrapolation argument found in [
12,
22], we obtain the following:
Theorem 5. Let Ω satisfy the conditions -. Suppose that h and Φ and ψ are given as in either Theorem 1, Theorem 2, Theorem 3, or Theorem 4.
If for some , then the inequality
holds for all ;
If , then the inequality
holds for all .
(1) The conditions on
in Theorem 5 are optimal. In fact, they are the weakest conditions in their particular classes, (see [
7,
9]).
(2) For the special cases
and
, the authors of [
18] confirmed the
(
boundedness of
whenever
for some
. This result is extended in Theorem 5 in which
.
(3) For the special case with , our results give the boundedness of for all which is the full range.
(4) For the special case
, Theorem 5 gives that
is bounded on
for all
, which is the result established in [
11]. Hence, our results essentially improve the main results in [
11].
(5) The surfaces of revolutions considered in our Theorems 1–5 cover several important natural classical surfaces. For instance, our theorems allow surfaces of the type with , with , is a polynomial, , where each is a convex increasing function with .
Henceforward, the constant C denotes a positive real constant which not necessary be the same at each occurrence but independent of all the essential variables.
3. Proof of main theorems
Assume that
for some
,
for some
and
. It is clear that Minkowski’s inequality leads to
For
, choose a set of smooth partition of unity
defined on
,
and adapted to the interval
with the following properties:
where
is independent of the lacunary sequence
.
Define the multiplier operators
on
by
. Hence, for any
, we have
, which gives by Minkowski’s inequality that
where
Therefore, to prove Theorem 1, it suffices to prove that for any
p satisfying
, there exists
such that
Let us first estimate the
-norm for
By Plancherel’s Theorem, Fubini’s Theorem, Lemma 2, we deduce
where
and
.
Next, we estimate the
-norm of
as follows: By employing a similar argument as that used in [
23] along with the Littlewood-Paley theory and Lemma 7, we get
Finally, by interpolating between and , we obtain , which in turn finishes the proof of Theorem 1.