- Research
- Open Access
- Published:
Inclusion results for certain subclasses of p-valent meromorphic functions associated with a new operator
Journal of Inequalities and Applications volume 2012, Article number: 169 (2012)
Abstract
In this paper, we introduce new subclasses of p-valent starlike, p-valent convex, p-valent close-to-convex, and p-valent quasi-convex meromorphic functions and investigate some inclusion properties of these subclasses and investigate various inclusion properties and integral-preserving properties for the p-valent meromorphic function classes.
MSC:30C45.
1 Introduction
Let denote the class of functions of the form
which are analytic and p-valent in the punctured unit disc . If and are analytic in , we say that is subordinate to , written or (), if there exists a Schwarz function in U with and , such that (). Furthermore, if is univalent in U, then the following equivalence relationship holds true (see [3] and [8]):
For functions , given by (1.1) and defined by
the Hadamard product (or convolution) of and is given by
Aqlan et al.[1] defined the operator by:
Now, we define the operator as follows:
First, put
and let be defined by
Then
Using (1.5)-(1.7), we have
where is in the form (1.1) and denotes the Pochhammer symbol given by
It is readily verified from (1.8) that
and
It is noticed that, putting in (1.8), we obtain the operator
Let M be the class of analytic functions with , which are convex and univalent in U and satisfy ().
For , , we denote by , , , and , the subclasses of consisting of all p-valent meromorphic functions which are, respectively, starlike of order η, convex of order η, close-to-convex functions of order γ and type η, and quasi-convex functions of order γ and type η in U.
Making use of the principle of subordination between analytic functions, we introduce the subclasses , , , and (, and ) of the class which are defined by:

and

From these definitions, we can obtain some well-known subclasses of by special choices of the functions ϕ and ψ as well as special choices of η, γ, and p (see [2, 5], and [10]).
Now, by using the linear operator (, , ; ) and for , , , we define new subclasses of meromorphic functions of by:

and
We also note that
and
In particular, we set
and
In this paper, we investigate several inclusion properties of the classes , , , and associated with the operator . Some applications involving integral operators are also considered.
In order to establish our main results, we need the following lemmas.
Lemma 1[4]
Let ς and υ be complex constants and letbe convex (univalent) in U withand. If
is analytic in U, then
implies
Lemma 2[7]
Letbe convex (univalent) in U andbe analytic in U with. If q is analytic in U and, then
implies
2 Some inclusion results
In this section, we give some inclusion properties for meromorphic function classes, which are associated with the operator . Unless otherwise mentioned, we assume that , , , , and .
Theorem 1 For, with
then we have
Proof We will first show that
Let and put
where is analytic in U with . Applying (1.10) in (2.3), we have
Differentiating (2.4) logarithmically with respect to z, we have
Since
we see that
Applying Lemma 1 to (2.5), it follows that , that is, that . The proof of the second part will follow by using arguments similar to those used in the first part with and using the identity (1.9) instead of (1.10). This completes the proof of Theorem 1. □
Theorem 2 For, with

Proof Applying (1.10) and using Theorem 1, we have
Also,
This completes the proof of Theorem 2. □
Taking
in Theorem 1 and Theorem 2, we have the following corollary.
Corollary 1 Let and
Then we have
and
Now, using Lemma 2, we obtain similar inclusion relations for the subclass .
Theorem 3 Let and
Then we have

Proof First, we will prove that
Let . Then, from the definition of the class , there exists a function such that
Now, let
where is analytic in U with . Applying (1.10) in (2.6), we have

Since, by Theorem 1,
set
where in U, and . Then, using (2.7) and (2.8), we have
and

Differentiating both sides of (2.9) with respect to z and multiplying by z, we have
Making use of (2.6), (2.10), and (2.11), we have
Since in U, and
then
Hence, putting
in Eq. (2.12) and applying Lemma 2, we can show that , that is, that . The second part can be proved by using similar arguments and using (1.9). This completes the proof of Theorem 3. □
3 Inclusion properties involving the integral operator
Now, we consider the generalized Libera integral operator (see [6] and [9]), defined by
From (3.1), we have
Theorem 4 Let with
If, then.
Proof Let and put
where h is analytic in U with . Then, by using (3.2) and (3.3), we have
Differentiating (3.4) logarithmically with respect to z, we have
Applying Lemma 1, we conclude that , which implies that . □
Theorem 5 Let with
If, then.
Proof Applying Theorem 4 and (1.12), we have
This completes the proof of Theorem 5. □
From Theorem 4 and Theorem 5, we have the following corollary.
Corollary 2 Suppose that
Then, for the classesand, the following inclusion relations hold true:
and
Theorem 6 Let with
If, then.
Proof Let . Then, from the definition of the class , there exists a function such that
Now, let
where is analytic in U with . Applying (3.2) in (3.6), we have

Since , then by Theorem 4, we have . Let
where in U. Then, using the same techniques as in the proof of Theorem 3 and using (3.5) and (3.7), we have
Since , then applying Lemma 2, we find that , which yields . This completes the proof of Theorem 6. □
Remark Putting in the above results, we obtain the results corresponding to the operator defined by (1.11).
Author’s contributions
The author read and approved the final manuscript.
References
Aqlan E, Jahangiri JM, Kulkarni SR: Certain integral operators applied to meromorphic p-valent functions. J. Nat. Geom. 2003, 24: 111–120.
Bajpai SK: A note on a class of meromorphic univalent functions. Rev. Roum. Math. Pures Appl. 1977, 22: 295–297.
Bulboaca T: Differential Subordinations and Superordinations. Recent Results. House of Scientific Book Publ., Cluj-Napoca; 2005.
Eenigenburg P, Miller SS, Mocanu PT, Reade MO: On a Briot-Bouquet differential subordination. Internat. Schriftenreihe Numer. Math. 64. In General Inequalities 3. Birkhäuser, Basel; 1983:339–348.
Goel RM, Sohi NS: On a class of meromorphic functions. Glasnik Math. III 1982, 17(37):19–28.
Libera RJ: Some classes of regular univalent functions. Proc. Am. Math. Soc. 1965, 16: 755–758. 10.1090/S0002-9939-1965-0178131-2
Miller SS, Mocanu PT: Differential subordinations and univalent functions. Mich. Math. J. 1981, 28(2):157–171.
Miller SS, Mocanu PT Series on Monographs and Textbooks in Pure and Applied Mathematics 225. In Differential Subordination: Theory and Applications. Dekker, New York; 2000.
Owa S, Srivastava HM: Some applications of the generalized Libera integral operator. Proc. Jpn. Acad., Ser. A, Math. Sci. 1986, 62: 125–128. 10.3792/pjaa.62.125
Singh R: Meromorphic close-to-convex functions. J. Indian Math. Soc. 1969, 33: 13–20.
Author information
Authors and Affiliations
Corresponding author
Additional information
Competing interests
The author declares that she has no competing interests.
Rights and permissions
Open Access This article is distributed under the terms of the Creative Commons Attribution 2.0 International License (https://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
About this article
Cite this article
Mostafa, A. Inclusion results for certain subclasses of p-valent meromorphic functions associated with a new operator. J Inequal Appl 2012, 169 (2012). https://doi.org/10.1186/1029-242X-2012-169
Received:
Accepted:
Published:
DOI: https://doi.org/10.1186/1029-242X-2012-169
Keywords
- p-valent meromorphic functions
- Hadamard product
- inclusion properties