TITLE MARCH 2012 - Pakistan Academy of Sciences
TITLE MARCH 2012 - Pakistan Academy of Sciences
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 />
.