Gen. Math. Notes, Vol. 20, No. 2, February 2014, pp.... ISSN 2219-7184; Copyright © ICSRS Publication, 2014

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Gen. Math. Notes, Vol. 20, No. 2, February 2014, pp. 79-94

ISSN 2219-7184; Copyright © ICSRS Publication, 2014 www.i-csrs.org

Available free online at http://www.geman.in

Some Geometric Properties of a Certain

Subclass of Univalent Functions Defined by

Differential Subordination Property

Waggas Galib Atshan

1

, A. H. Majeed

2

and Kassim A. Jassim

3

1

Department of Mathematics

College of Computer Science and Mathematics

University of Al-Qadisiya, Diwaniya-Iraq

E-mail: waggashnd@gmail.com; waggas_hnd@yahoo.com

2,3

Department of Mathematics, College of Science

University of Baghdad, Baghdad-Iraq

2

Email: ahmajeed6@yahoo.com

3

E-mail: kasim.hameed@yahoo.com

(Received: 16-10-13 / Accepted: 9-12-13)

Abstract

In this paper , we have studied a certain subclass of univalent functions defined by linear operator

, ,

by using differential subordination property.We obtain some geometric properties, like , coefficient inequality , neighborhoods of the class K(

, , , , , , , ),

convolution properties and integral mean inequalities for the fractional integral for this class.

Keywords: Univalent Function, Hypergeometric Function, Linear Operator,

Differential Subordination, Convolution, Integral Mean, Fractional Integral.

80 Waggas Galib Atshan et al.

1 Introduction

Let S denote the class of functions of the form:-

) = + , 1) which are analytic in the open unit disk U={z

∈ ¢: | | < 1}

. Also, denoted by K the subclass of S consisting of functions of the form:-

) = − | | , 2) which are univalent and normalized in U.

For ∈ S, and of the form 1)and 4 ) ∈ S given by 4 ) = + : ,

We define the Hadamard product (or convolution)

∗ 4) ) = + : . 3)

For positive real values of

, … . ,

and

? , … . , ?

(

?

1,2, … . ),

@

≠ 0, −1, … . , C =

The generalized hypergeometric function

δ

F m

(z) is defined by

D

F

E z) ≡

D

F

E

, … , ; ? , … , ? ; )

=

) … )

? ) … ? )

(

≤ + 1

;

, ∈ N

I

I

= N ∪ P0}; ∈ Q), where

)

is the Pochhammer symbol defined by

J! 4)

+ 1) + 2) … + J − 1), J ∈ N.

S 5)

The notation

δ

F m

is quite useful for representing many well-known functions such as the exponential, the Binomial, the Bessel and Laguerre polynomial.

Some Geometric Properties of a Certain... 81

H[ , ,

W be a linear operator defined by

… . , ; ? , ? , ?

W

… . , ? ]: K → K

H[

, … , ; ? , … , ? ] ) = z

δ

F m

(

, , … , ; ? , ? , … , ? ; ) ∗ )

= − [ ; ; )| | , 6) where,

[ ; ; ) =

? )

)

]

]

… )

… ? )

]

]

1

J − 1)! . 7)

For notational simplicity, we use shorter notation

_ [ ] for

H[

, … , ; ? , … , ?

].

In the sequel .It follows from (6) that

_

I

[1] ) = ), _

I

[2] ) = ` ).

The linear operator

_ [ ]

is called Dziok-Srivastava operator (see [5]) introduced by Dziok and Srivastava which was subsequently extended Dziok and

Raina [4] by using the generalized hypergeometric function, recently Srivastava et. al. [13] defined the linear operator

,

, ,

as follows:-

I,

, ,

) = )

,

, ,

) = 1 − )_ [ ] ) + a_ [ ] )b

`

=

, ,

), 8)

,

, ,

) =

, , a ,

, ,

)b, 9) and in general,

,

, ,

) =

, , a ] ,

, ,

)b , 0 ≤ ≤ 1, ≤ + 1; , ∈ N

I

= N ∪ P0} ; ∈ Q). 10)

If the function f(z) is given by (2), then we see from (6),(7),(8) and (10) that

,

, ,

) = − [ ; ; ; )| | , 11) where

82 Waggas Galib Atshan et al.

[ ; ; ; ) = e

? )

)

]

]

… )

… ? )

]

]

[1 + J − 1)]

J − 1)! f , 12)

J ∈ N\P1}, ∈ N

I ) .

Unless otherwise stated .We note that when

= 1 and

= 0

, the linear operator

,

, ,

would reduce to the familier Dziok-Srivastava linear operator given by(see[5]), includes (as its special cases) various other linear operators introduced and studied by Carlson and Shaffer [3], Owa [9] and Ruscheweyh [10].

For two analytic functions f,

4 ∈

K , we say that f is subordinate to

4

written

f(z)

≺ 4

(z) if there exists a schwarz function w(z), which (by definition) is analytic in U with w(0)=0 and |w(z)|<1 for all z

∈ Q such that f(z)=

4

(w(z)),z

∈ Q

.

Furthermore, if the function

4

(z) is univalent in U, then we have the following equivalence (see [8]):

f(z)

≺ 4

(z)

f(0)=

4

(0) and f(U) ⊂

4

(U).

Definition (1): For any function f

K and

∅ ≥ 0

, the

∅ − Jlm4ℎ:opℎooq

f is

defined as,

N

,∅

) = P4 ) = − |: | ∈ r; J|| | − |: || ≤ ∅}. (13)

In particular, for the function e(z)=z, we see that,

N

,∅

(l) = {4( ) = − |: | ∈ r; J| : | ≤ ∅}. (14)

The concept of neighborhoods was first introduced by Goodman [6] and then generalized by Ruscheweyh [11] , and studied by some authors, like Atshan [1] and Atshan and Kulkarni [2].

Definition (2): For fixed parameters A and B, with -1

≤ < ≤ 1

, we say that f

∈ r

is in class K(

, , , , , , , ), if it satisfies the following subordination

condition:

1 +

(

( st,

, ,

,

, ,

( ))′′

( ))′

1 +

1 +

. (15)

In view of the definition of subordination, (15) is equivalent to the following condition:

Some Geometric Properties of a Certain... 83 v v

(

( st,

, ,

,

, ,

(

(

For convenience, we write st,

, ,

,

, ,

( ))′′

( ))′

( ))′′

( ))′ + ( − ) v v < 1, ( ∈ Q).

K(

, , , , , , 1 − 2w, −1) = K( , , , , , , w), where

K( , , , , , , w) denotes the class of functions in K satisfying the inequality:

Re y1 +

( a st,

, ,

,

, ,

( ))′′

( )b

` z > w, 0 ≤ w < 1; ∈ Q).

2 Neighborhoods for the Class K(

|, }, ~

, €, •, ‚, ƒ, „)

The following theorem gives a necessary and sufficient condition for a function f to be in the class K(

, , , , , , , ).

Theorem (1): A function f

∈ r

belong to the class K(

, , , , , , , )

if and only if

J(2J − 1) [ ( ; ; ; ) a(1 − )[ t ( ; ; ; ) + ( − )b | |

≤ − ) , 16) for

, , ∈ N

I

, ≤ + 1, ≥ 0 Jq − 1 ≤ < ≤ 1.

Proof: Let f

K(

, , , , , , , )

. Then

1 + st,

, ,

,

, ,

))′′

))′

1 +

1 +

, ∈ Q . 17)

Therefore, there exists an analytic function w such that

… ) = st,

, , st,

, ,

))′′

))′′ + − ) ,

, ,

))′

. 18)

84 Waggas Galib Atshan et al.

Hence,

|…( )| = †

( st,

, ,

( st,

, ,

( ))′′

( ))′′ + ( − )( ,

, ,

( ))′

= ‡

− ∑ J(J − 1) [ st ( ; ; ; )| |

( − ) − ∑ J [ ( ; ; ; ) a [ t ( ; ; ; ) + ( − )b | |

< 1.

Thus,

∑ J(J − 1) [ st ( ; ; ; )| |

( − ) + ∑ J [ ( ; ; ; )( [ t ( ; ; ; ) + ( − ))| |

‰ < 1.

Therefore,

Šl ‹

∑ J(J − 1) [ st ( ; ; ; )| |

( − ) + ∑ J [ ( ; ; ; )( [ t ( ; ; ; ) + ( − ))| |

Œ

< 1. (19)

Taking |z|=r, for sufficiently small r with 0<r<1, since w(z) is analytic for

|z|=1.Then , the inequality (19) yields

J(J − 1) [ st ( ; ; ; )| |p

< ( − )p + J [ ( ; ; ; ) a [ t ( ; ; ; ) − ( − )b | |p .

Equivalently,

J(2J − 1) [ ( ; ; ; )((1 − ) [ t ( ; ; ; ) + ( − ))| |p

≤ ( − )p and (16) follows upon letting r

1.

Conversely, for |z|=r, 0<r<1, we have r n

<r. That is,

J(2J − 1) [ ( ; ; ; )((1 − ) [ t ( ; ; ; ) + ( − ))| |p

Some Geometric Properties of a Certain... 85

≤ J(2J − 1) [ ( ; ; ; )((1 − ) [ t ( ; ; ; ) + ( − )) | |p

≤ − )p

.

From (16), we have

† J J − 1) [ st ; ; ; )| | †

≤ J J − 1) [ st ; ; ; )| |p

< − )p + J [ ; ; ; ) [ t ; ; ; ) + − ))| |p

< | − ) + J [ ; ; ; ) [ t ; ; ; ) + − ))| | |.

This proves that

1 + st,

, ,

,

, ,

))′′

))′ and hence f

K(

, , , , , , , )

.

1 +

1 +

Theorem (2): If

, ∈ Q,

∅ =

3 e

) … )

? ) … ? ) 1 + )f • 1 − )

) … )

? ) … ? ) 1 + )) t + − )Ž then K(

, , , , , , , )

N

•,∅ e).

Proof: It follows from (16), that if f

K(

, , , , , , , )

, then

, 20)

3 [ ; ; ; ) a1 − ) [ t ; ; ; ) + − )b J| | ≤ − .

Hence

3

) … )

? ) … ? ) 1 + )) ‘ 1 − ) e

) … )

? ) … ? ) 1 + )f t

+ − )’

86 Waggas Galib Atshan et al.

× J | | ≤ − , 21) which implies that

J| | ≤

3

) … )

? ) … ? ) 1 + )) ‘ 1 − ) ”

) … )

? ) … ? ) 1 + )• t

+ − )’

=

(22)

Using (14), we get the result.

Definition (3): The function

4

defined by

4

(z)=

− ∑

|: | member of the class K c f

K(

, , , , , , , )

such that

is said to be a

(

, , , , , , , )

if there exist a function

4 )

) − 1– ≤ 1 − — ,

∈ Q, 0 ≤ — < 1). 23)

Theorem (3): If f

K(

, , , , , , , ) and

— = 1 −

6 [

3 ∅ [ ; ; ; ) 1 − ) [ ; ; ; ) + − ))

; ; ; ) 1 − )[ ; ; ; ) + − )) − − )

, 24) then

N

•,∅

)

⊂ K c

(

, , , , , , , ).

Proof: Let

4 ∈ N

•,∅

).

Then we have from (13) that

J|| | − |: || ≤ ∅, which implies the coefficient inequality

|| | − |: || ≤

2.

Also, since f

K(

, , , , , , , )

, we have from (16)

| | ≤

6 [

, , , ) 1 − ) [ t ; ; ; ) + − ))

,

Some Geometric Properties of a Certain... 87 where

[

[ ( ; ; ; ) = (

( ) … ( )

(? ) … (? ) (1 + )) , t ( ; ; ; ) = (

( ) , … . , ( )

(? ) , … . , (? ) (1 + )) t , so that

4( )

( ) − 1– = ‰

∑ (| | − |: |)

− ∑ | |

‰ <

∑ || | − |: ||

1 − ∑ | |

≤ ∅.

3 [ ( ; ; ; )((1 − ) [

6 [ ( ; ; ; )((1 − ) [ t t ( ; ; ; ) + ( − ))

( ; ; ; ) + ( − )) − ( − )

=1-c.

Thus by Definition (3),

4 ∈

K c

(

, , , , , , , )

for c given by (24).

This completes the proof.

3 Convolution Properties

Theorem (4): Let the functions f j

(j=1,2) defined by

@

( ) = − |

,@

| , (C = 1,2), (25) be in the class K(

, , , , , , , )

.Then f

1 where

*f

2

∈ K( , , , , , , , ˜)

,

˜ ≤

J(2J − 1) [ ( ; ; ; )((1 − ) [ t

J(2J − 1) [ ( ; ; ; )((1 − ) [ t

( ; ; ; ) + ( − )) − ( − ) ( + [ t

( ; ; ; ) + ( − )) − ( − ) (1 + [ t

( ; ; ; ))

( ; ; ; ))

Proof: We must find the largest

˜

such that

J(2J − 1) [ ( ; ; ; )(a1 − ˜) [ t ( ; ; ; ) + ( − ˜)b

− ˜

,

™|

,

| ≤ 1.

Since @

∈ K( , , , , , , , )(C = 1,2), then

J(2J − 1) [ ( ; ; ; )(a1 − ) [ t ( ; ; ; ) + ( − )b

By Cauchy –Schwarz inequality, we get

,@

™ ≤ 1 , ( C = 1,2). (26)

88 Waggas Galib Atshan et al.

J(2J − 1) [ ( ; ; ; )((1 − ) [ t

( ; ; ; ) + ( − ))

š™

,

™|

,

| ≤ 1 . (27)

We want only to show that

J(2J − 1) [ ( ; ; ; )((1 − ˜) [

− ˜

J(2J − 1) [ ( ; ; ; )((1 − ) [

− t t

( ; ; ; ) + ( − ˜))

( ; ; ; ) + ( − ))

š™

,

™|

,

™|

,

| ≤

,

|.

This equivalently to

š™

,

™|

,

| ≤

( − ˜)((1 − ) [

( − )((1 − ˜) [ t t

( ; ; ; ) + ( − ))

( ; ; ; ) + ( − ˜))

.

From (27), we have

š™

,

™|

,

| ≤

J(2J − 1) [ ( ; ; ; )((1 − ) [ t ( ; ; ; ) + ( − ))

.

Thus, it is sufficient to show that

J(2J − 1) [ ( ; ; ; )((1 − ) [ t ( ; ; ; ) + ( − ))

( − ˜)((1 − ) [

( − )((1 − ˜) [ t t

( ; ; ; ) + ( − ))

( ; ; ; ) + ( − ˜))

,

≤ which implies to

˜ ≤

J(2J − 1) [ ( ; ; ; )((1 − ) [

J(2J − 1) [ ( ; ; ; )((1 − ) [ t t ( ; ; ; ) + ( − )) − ( − ) ( + [ t

( ; ; ; ) + ( − )) − ( − ) (1 + [ t

( ; ; ; ))

( ; ; ; ))

This completes the proof.

Theorem (5): Let the functions f j

(j=1, 2) defined by (25) be in the class r( , , , , , , , ).

Then the function h defined by

ℎ( ) = − (|

,

| + |

,

| ) (28) belong to the class

K( , , , , , , , ›)

, where

Some Geometric Properties of a Certain... 89

› ≤

J(2J − 1) [ ( ; ; ; )((1 − ) [ t

J(2J − 1) [ ( ; ; ; )((1 − ) [ t

( ; ; ; ) + ( − )) − 2[ t ( ; ; ; )( − ) − 2( − )

( ; ; ; ) + ( − )) + 2 ( − ) + 2[ t ( ; ; ; )( − )

Proof: We must find the largest

such that

J(2J − 1) [ ( ; ; ; ) a(1 − ›) [ t ( ; ; ; ) + ( − ›)b

− ›

(™

,

™ + ™

,

™ ) ≤ 1.

Since @

∈ K( , , , , , , , ) (C = 1,2), we get e

J(2J − 1) [ ( ; ; ; )((1 − ) [

− t ( ; ; ; ) + ( − )) f ™

,

≤ •

J(2J − 1) [ ( ; ; ; )((1 − ) [ t

( ; ; ; ) + ( − ))

,

™ž ≤ 1 , (29) and e

J(2J − 1) [ ( ; ; ; )((1 − ) [

− t ( ; ; ; ) + ( − )) f ™

,

≤ •

J(2J − 1) [ ( ; ; ; )((1 − ) [

− t ( ; ; ; ) + ( − ))

Combining the inequalities (29) and (30), gives

1

2 e

J(2J − 1) [ ( ; ; ; )((1 − ) [

− t ( ; ; ; ) + ( − )) f ™

,

™ + ™

,

™ž ≤ 1. (30)

,

™ ≤ 1 . (31)

But ℎ ∈ K( , , , , , , , ›)

if and only if

(

J(2J − 1) [ ( ; ; ; )((1 − ›) [

− › t ( ; ; ; ) + ( − ›))

(™

,

™ + ™

,

™ ) ≤ 1 . (32)

The inequality (32) will be satisfied if

J(2J − 1) [ ( ; ; ; )((1 − ›) [

− › t ( ; ; ; ) + ( − ›))

(J(2J − 1) [ ( ; ; ; )((1 − ) [ t

2( − )

( ; ; ; ) + ( − ))

, (J = 2,3, … ) , (33)

90 Waggas Galib Atshan et al. so that,

› ≤

J(2J − 1) [ ( ; ; ; )((1 − ) [ t

J(2J − 1) [ ( ; ; ; )((1 − ) [ t

( ; ; ; ) + ( − )) − 2[ ( ; ; ; )( − ) − 2( − )

( ; ; ; ) + ( − )) + 2 ( − ) + 2[ ( ; ; ; )( − )

This completes the proof.

4 Integral Mean Inequalities for the Fractional

Integral

Definition (4) [12]: The fractional integral of order s (s>0) is defined for a

function f by:

Ÿ ]¡ ( ) =

1

Γ

(¢) £

I

(¤)

( − ¤) ]¡ q¤ , where the function f is an analytic in a simply- connected region of the complex zplane containing the origin , and multiplicity of

( − ¤) ¡]

is removed by requiring log(z-t) to be real, when (z-t)>0.

In 1925, Littlewood [7] proved the following subordination theorem:-

Theorem (6) (Littlewood [7]): If f and

4

are analytic in U with f w > 0 and

= pl ¥¦

(0<r<1)

≺ 4

, then for

¨

£ | ( )| §

I

¨ q ≤ £ |4( )| §

I q

Theorem (7): Let f

∈ r( , , , , , , , )

and suppose that f n

is defined by

( ) = −

J(2J − 1) [ ( ; ; ; )((1 − ) [ t ( ; ; ; ) + ( − ))

, (J ≥ 2). (34)

Also, let

(m − ©)

ªs

|

¥

|

( − )

Γ

(J + 1)

Γ

(¢ + © + 3)

J(2J − 1) [ ( ; ; ; )((1 − ) [ t ( ; ; ; ) + ( − ))

Γ

(J + ¢ + © + 1)

Γ

(2 − ©)

, (35) for

0 ≤ © ≤ m, ¢ > 0

, where

(m − ©) by

(m − ©)

ªs

= (m − ©)(m − © + 1) … m.

denote the Pochhammer symbol defined

If there exists an analytic function q defined by

Some Geometric Properties of a Certain... 91

«¬( )-

]

=

J(2J − 1) [ ( ; ; ; )(1 − ) [ t ( ; ; ; ) + ( − ))

Γ

(J + ¢ + © + 1)

( − )

Γ

(J + 1)

× (m − ©)

ªs

¥ where i

≥ ©

and

_(m)|

¥

| ¥] , (36)

_(m) =

Γ

(m − ©)

Γ

(m + ¢ + © + 1), (¢ > 0, m ≥ 2), (37) then , for z = pl

¨

£ |Ÿ

I

]¡]ª ( )| §

¥ ϕ and 0 < p < 1

¨ q ϕ

≤ £ |Ÿ

I

]¡]ª

Proof: Let

( ) = − ∑ |

¥

| ¥

( )|

.

§

For q ϕ

(¢ > 0, w > 0) . (38)

© ≥ 0

and Definition (4), we get

Ÿ ]¡]ª ( ) =

Γ

(2) ¡sªs

Γ

(¢ + © + 2) (1 −

¥

Γ

Γ

(m + 1)

(2)

Γ

Γ

(¢ + © + 2)

(m + ¢ + © + 1)

|

¥

| ¥] )

=

Γ

(2) ¡sªs

Γ

(¢ + © + 2) •1 −

¥

Γ

(¢ + © + 2)

Γ

(2)

(m − ©)

ªs

_(m)|

¥

| ¥] ž, where

_(m) =

Γ

(m − ©)

Γ

(m + ¢ + © + 1) ,

(¢ > 0, m ≥ 2)

Since H is a decreasing function of i, we have

0 < _(m) ≤ _(2) =

Γ

(2 − ©)

Γ

(¢ + © + 3).

Similarly, from (34) and Definition (4), we get

Ÿ ]¡]ª ( ) =

Γ

(2) ¡sªs

Γ

(¢ + © + 2) (1 −

( − )

Γ

(J + 1)

Γ

(¢ + © + 2)

J(2J − 1) [ ( ; ; ; )((1 − ) [ t ( ; ; ; ) + ( − ))

Γ

(J + ¢ + © + 1)

For w > 0, and z = pl ¥ ϕ (0 < p < 1)

, we must show that

] ).

92 Waggas Galib Atshan et al.

¨

£ †1 −

I

Γ

(¢ + © + 2)

Γ

(2)

(m − ©)

ªs

_(m) |

¥

| ]¥ † q ϕ

¨

≤ £ |1 −

¥

I

(A − B)

Γ

(J + 1)

Γ

(¢ + © + 2)

J(2J − 1) [ ( ; ; ; )((1 − ) [ t ( ; ; ; ) + ( − ))

Γ

(2)

Γ

(J + ¢ + © + 1)

] | § q ϕ

.

By applying Littlewood’s subordination theorem, it would suffice to show that

1 − ∑

¥

Γ

(¡sªs )

Γ

( )

(m − ©)

ªs

_(m) |

¥

| ¥] ≺

1-

(A − B)

Γ

(J + 1)

Γ

(¢ + © + 2)

J(2J − 1) [ ( ; ; ; )((1 − ) [ t ( ; ; ; ) + ( − ))

Γ

(2)

Γ

(J + ¢ + © + 1)

] .

By setting

1 −

Γ

(¢ + © + 2)

Γ

(2)

(m − ©)

ªs

_(m) |

¥

| ¥]

¥

=

(A − B)

Γ

(J + 1)

Γ

(¢ + © + 2)

J(2J − 1) [ ( ; ; ; )((1 − ) [ t ( ; ; ; ) + ( − ))

Γ

(2)

Γ

(J + ¢ + © + 1)

«¬( )we find that

«¬( )-

]

=

J(2J − 1) [ ( ; ; ; )((1 − ) [ t ( ; ; ; ) + ( − ))

Γ

(J + ¢ + © + 1)

(A − B)

Γ

(J + 1)

]

,

× (m − ©)

ªs

¥

_(m) |

¥

| ¥] , which readily yields w(0)=0.For such a function q , we obtain

«¬( )-

]

J(2J − 1) [ ( ; ; ; ) a(1 − ) [ t ( ; ; ; ) + ( − )b

Γ

(J + ¢ + © + 1)

(A − B)

Γ

(J + 1)

× (m − ©)

ªs

¥

_(m) |

¥

|| | ¥]

J(2J − 1) [ ( ; ; ; ) a(1 − ) [ t ( ; ; ; ) + ( − )b

Γ

(J + ¢ + © + 1)

(A − B)

Γ

(J + 1)

× _(2)| | (m − ©)

ªs

¥

|

¥

|

Some Geometric Properties of a Certain... 93

= | |

J(2J − 1) [ ( ; ; ; )((1 − ) [ t ( ; ; ; ) + ( − ))

Γ

(J + ¢ + © + 1)

(A − B)

Γ

(¢ + © + 3)

Γ

(J + 1)

×

Γ

(2 − ©) (m − ©)

ªs

¥

This completes the proof.

|

¥

| ≤ | | < 1.

By taking

τ = 0

, in the Theorem 7, we have the following corollary:

Corollary (1): Let f

∈ r( , , , , , , , )

, and suppose that is defined by

(34). Also let m|

¥

| ≤

(A − B)

Γ

(J + 1)

Γ

(¢ + 3)

J(2J − 1) [ ( ; ; ; )((1 − ) [ t ( ; ; ; ) + ( − ))

Γ

(2)

Γ

(J + ¢ + 1)

¥ n

≥ 2

. If there exists an analytic function q defined by

«¬( )-

]

=

J(2J − 1) [ ( ; ; ; ) a(1 − ) [

(A − B) t

Γ

( ; ; ; ) + ( − )b

Γ

(J + ¢ + 1)

(J + 1)

× m_(m) |

¥

¥

| ¥] , where

Then for

z = pl ¥ ϕ

¨

£ |Ÿ

I

_(m) =

and 0 < p < 1

( )| § q ϕ

Γ

(m)

Γ

(m + ¢ + 1) , ( ¢ > 0, m ≥ 2).

≤ £ |Ÿ

I

¨

]¡ ( )| § q (¢ > 0, w > 0) .

References

[1] W.G. Atshan, Subclass of meromorphic functions with positive coefficients defined by Ruscheweyh derivative II, J. Surveys in

Mathematics and its Applications, 3(2008), 67-77.

[2] W.G. Atshan and S.R. Kulkarni, Neighborhoods and partial sums of subclass of k-uniformly convex functions and related class of k-starlike functions with negative coefficient based on integral operator, J. Southeast

Asian Bulletin of Mathematics, 33(4) (2009), 623-637.

94 Waggas Galib Atshan et al.

[3] B.C. Carlson and D.B. Shaffer, Starlike and prestarlike hypergeometric functions, SIAM J. Math. Anal., 15(1984), 737-745.

[4] J. Dziok and R.K. Raina, Families of analytic functions associated with the

Wright generalized hypergeometric functions, Demonstration Math., 37(3)

(2004), 533-542.

[5] J. Dziok and H.M. Srivastava, Certain subclasses of analytic functions associated with the generalized hypergeometric function, Integral

Transform Spec. Funct., 14(2003), 7-18.

[6] A.W. Goodman, Univalent functions and non-analytic curves, Proc. Amer.

Math. Soc., 8(3) (1975), 598-601.

[7] L.E. Littlewood, On inequalities in the theory of functions, Proc. London

Math. Soc., 23(1925), 481-519.

[8] S.S. Miller and P.T. Mocanu, Differential subordinations: Theory and applications, Series on Monographs and Textbooks in Pure and Applied

Mathematics (Vol.225), Marcel Dekker, New York and Basel, (2000).

[9] S. Owa, On the distortion the theorems, I. Kynngpook Math. J., 18(1978),

53-59.

[10] S. Ruscheweyh, New criteria for univalent functions, Proc. Amer. Math.

Soc., 49(1975), 109-115.

[11] S. Ruscheweyh, Neighborhoods of univalent functions, Proc. Amer. Math.

Soc., 81(1981), 521-527.

[12] H.M. Srivastava and S. Owa (Eds), Current Topics in Analytic Function

Theory, World Scientific Publishing Company, Singapore, (1992).

[13] H.M. Srivastava, S.H. Li and H. Tang, Certain classes of k-uniformly close to convex functions and other related functions defined by using

Dziok-Srivastava operator, Bull. Math. Anal. Appl., 1(3) (2009), 49-63.

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