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TITLE MARCH 2012 - Pakistan Academy of Sciences

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Inclusion Properties <strong>of</strong> Certain Operators 59<br />

J<br />

, p( f )( z)<br />

S<br />

<br />

<br />

,<br />

p(<br />

a,<br />

b,<br />

c;<br />

)<br />

( S) .<br />

<br />

Pro<strong>of</strong> . Let f ( z)<br />

S<br />

,<br />

( a,<br />

b,<br />

c;<br />

)<br />

for S<br />

, and<br />

set<br />

z(<br />

I<br />

pI<br />

,<br />

p<br />

,<br />

p<br />

( a,<br />

b,<br />

c)<br />

J<br />

( a,<br />

b,<br />

c)<br />

J<br />

, p<br />

, p<br />

p<br />

( f )( z))<br />

<br />

q(<br />

z)<br />

,<br />

( f )( z)<br />

(3.2)<br />

2<br />

where q ( z)<br />

1<br />

q1z<br />

q2z<br />

...<br />

is analytic in<br />

U and q ( z)<br />

0 for all z U . From (3.1), we<br />

obtain<br />

z( I, p ( a, b, c) J, p ( f )( z)) ( p) I,<br />

p ( a, b, c) f ( z)<br />

(3.3)<br />

I ( a, b, c) J ( f )( z) ( z U) .<br />

, p<br />

,<br />

p<br />

By applying (3.2) and (3.3), we obtain<br />

I,<br />

p(<br />

a,<br />

b,<br />

c)<br />

f ( z)<br />

( p)<br />

pq(<br />

z)<br />

<br />

.<br />

I ( a,<br />

b,<br />

c)<br />

J ( f )( z)<br />

,<br />

p<br />

, p<br />

(3.4)<br />

Differentiating (3.4) logarithmically with respect<br />

to z , we obtain<br />

z(<br />

I<br />

I<br />

,<br />

p<br />

,<br />

p<br />

( a,<br />

b,<br />

c)<br />

f ( z))<br />

zq(<br />

z)<br />

q(<br />

z)<br />

.<br />

( a,<br />

b,<br />

c)<br />

f ( z)<br />

pq(<br />

z)<br />

<br />

Since<br />

from (3.5), we have<br />

Re<br />

(3.5)<br />

<br />

p, ( z)<br />

S<br />

, and f ( z)<br />

S<br />

,<br />

( )<br />

,<br />

zq(<br />

z)<br />

pq(<br />

z)<br />

<br />

p<br />

p(<br />

z)<br />

0 and q(<br />

z)<br />

(<br />

z)<br />

( z U)<br />

.<br />

Hence, by virbure <strong>of</strong> Lemma 1, we conclude<br />

that q( z)<br />

(<br />

z)<br />

( zU)<br />

,<br />

which implies that<br />

J<br />

, p( f )( z)<br />

S<br />

<br />

<br />

,<br />

p(<br />

a,<br />

b,<br />

c;<br />

)<br />

( S) .<br />

Next, we derive an inclusion property<br />

involving , which is given by<br />

J , p<br />

Theorem 5. Let p, p,<br />

a p and<br />

p . If f ( z)<br />

K<br />

, p(<br />

a,<br />

b,<br />

c;<br />

)<br />

( S)<br />

, then<br />

J<br />

, p( f )( z)<br />

K,<br />

p(<br />

a,<br />

b,<br />

c;<br />

)<br />

( S) .<br />

<br />

Pro<strong>of</strong> . By applying Theorem 4, it follows that<br />

zf (<br />

z)<br />

<br />

f ( z)<br />

K, p(<br />

a,<br />

b,<br />

c;<br />

)<br />

S,<br />

p(<br />

a,<br />

b,<br />

c;<br />

)<br />

p<br />

zf ( z)<br />

<br />

J, p<br />

S,<br />

p( a, b, c; )<br />

p <br />

z <br />

J , p( f )( z ) S<br />

<br />

,<br />

p( a , b , c ; )<br />

p<br />

J f )( z)<br />

K<br />

( a,<br />

b,<br />

c;<br />

)<br />

( <br />

, p( ,<br />

p<br />

S<br />

which proves Theorem 5.<br />

Finally, we prove<br />

Theorem 6. Let<br />

) ,<br />

p, p,<br />

a p and<br />

p . If f ( z)<br />

C<br />

, p(<br />

a,<br />

b,<br />

c;<br />

,<br />

) ( ,<br />

S)<br />

, then<br />

<br />

J<br />

, p( f )( z)<br />

C<br />

, p(<br />

a,<br />

b,<br />

c;<br />

,<br />

) ( ,<br />

S) .<br />

Pro<strong>of</strong>. Let f ( z)<br />

C<br />

,<br />

( a,<br />

b,<br />

c;<br />

,<br />

) for , S<br />

.<br />

p<br />

Then, in view <strong>of</strong> (1.7), there exists a function<br />

<br />

g( z)<br />

S<br />

,<br />

( a,<br />

b,<br />

c;<br />

)<br />

such that<br />

z(<br />

I<br />

pI<br />

,<br />

p<br />

,<br />

p<br />

p<br />

( a,<br />

b,<br />

c)<br />

f ( z))<br />

<br />

( z)<br />

( z U) . (3.6)<br />

( a,<br />

b,<br />

c)<br />

g(<br />

z)<br />

Thus we set<br />

z(<br />

I ( a,<br />

b,<br />

c)<br />

J<br />

pI<br />

,<br />

p<br />

,<br />

p<br />

( a,<br />

b,<br />

c)<br />

J<br />

, p<br />

, p<br />

( f )( z))<br />

<br />

q(<br />

z)<br />

,<br />

( f )( z)<br />

2<br />

where q ( z)<br />

1<br />

q1z<br />

q2z<br />

...<br />

is analytic in<br />

U and q ( z)<br />

0 for all z U . Applying (3.3), we<br />

get<br />

( )<br />

I<br />

,<br />

( a,<br />

b,<br />

c)<br />

zf <br />

p<br />

z(<br />

I<br />

,<br />

( a,<br />

b,<br />

c)<br />

f ( z))<br />

p z <br />

<br />

<br />

p<br />

<br />

<br />

pI ( a,<br />

b,<br />

c)<br />

g(<br />

z)<br />

I ( a,<br />

b,<br />

c)<br />

g(<br />

z)<br />

,<br />

p<br />

<br />

z<br />

I<br />

<br />

<br />

z<br />

<br />

<br />

z<br />

I<br />

<br />

,<br />

p<br />

( a,<br />

b,<br />

c)<br />

J<br />

,<br />

p<br />

( a,<br />

b,<br />

c)<br />

J<br />

<br />

I<br />

( a,<br />

b,<br />

c)<br />

J ( g)(<br />

z)<br />

I<br />

( a,<br />

b,<br />

c)<br />

J ( g)(<br />

z)<br />

,<br />

p<br />

,<br />

p<br />

, p<br />

<br />

zf<br />

( )<br />

p z <br />

<br />

<br />

I<br />

<br />

, p<br />

<br />

( a,<br />

b,<br />

c)<br />

J<br />

, p <br />

<br />

I ( a,<br />

b,<br />

c)<br />

g<br />

,<br />

p<br />

z I<br />

,<br />

I<br />

,<br />

p<br />

,<br />

p<br />

, p<br />

, p<br />

zf (<br />

)<br />

p z <br />

<br />

<br />

z f ( ) <br />

(<br />

) <br />

p z <br />

I<br />

,<br />

( a,<br />

b,<br />

c)<br />

J<br />

, <br />

zf<br />

p<br />

p <br />

<br />

p z<br />

<br />

<br />

<br />

( z)<br />

I<br />

,<br />

p<br />

( a,<br />

b,<br />

c)<br />

J<br />

, pg(<br />

z)<br />

<br />

p<br />

( a,<br />

b,<br />

c)<br />

J<br />

, p<br />

( g)(<br />

z)<br />

<br />

<br />

, p<br />

( a,<br />

b,<br />

c)<br />

J<br />

, pg(<br />

z)<br />

(3.7)<br />

<br />

<br />

<br />

Since g( z)<br />

S<br />

<br />

, p(<br />

a,<br />

b,<br />

c;<br />

)<br />

( S)<br />

, by virtue<br />

<br />

<br />

<strong>of</strong> Theorem 4, we have J g)(<br />

z)<br />

S ( a,<br />

b,<br />

c;<br />

) .<br />

Let us now put<br />

, p( ,<br />

p<br />

<br />

.

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