Global Journal of Pure and Applied Mathematics.
ISSN 0973-1768 Volume 13, Number 8 (2017), pp. 4099–4109
© Research India Publications
http://www.ripublication.com/gjpam.htm
Some growth of composite entire and meromorphic
functions with finite iterated order
Samten Tamang
Department of Mathematics,
The University of Burdwan, Burdwan,
Pin - 713104, West Bengal, India.
Nityagopal Biswas
Department of Mathematics,
University of Kalyani, Kalyani,
Dist. Nadia, PIN - 741235, West Bengal, India.
Abstract
The object of this paper is to investigate the growth properties of composite entire
and meromorphic functions with finite iterated order. We have established some
new results which are the improvement and extensions of the earliar results.
AMS subject classification: 30D35, 30D30.
Keywords: Entire function, Meromorphic function, Composition, Finite iterated
order.
1. Introduction, Definitions and Notations
We will assume that the reader is familiar with the standard notations and the fundamental
results employed in the theory of entire and meromorphic functions, see [18] and [5].
Let f be a entire function with M (r, f ) = max
|z|=r
|f (z)|. A well known theorem of
Polya [13] asserts that: If f and g are entire functions, then the composite function
f ◦ g is of infinite order unless (a) f is of finite order and g is a polynomial or (b) f is
of order zero and g is of finite order. For the two transcendental entire functions f (z)
and g (z), Clunie [4] showed that lim
r →∞
T (r, f ◦ g)
T (r, f )
=∞ and lim
r →∞
T (r, f ◦ g)
T (r, g)
=∞ .