Advances in Pure Mathematics
Vol.3 No.3(2013), Article ID:31231,8 pages DOI:10.4236/apm.2013.33048
Wright Type Hypergeometric Function and Its Properties
1Department of Applied Mathematics, The M.S. University of Baroda, Vadodara, India
2Department of Mathematical Sciences, Faculty of Applied Sciences, Charotar University of Science and Technology, Anand, India
3Department of Applied Mathematics and Humenities, S.V. National Institute of Technology, Surat, India
Email: sbr_msub@yahoo.com, jyotindra18@rediffmail.com, ajayshukla2@rediffmail.com
Copyright © 2013 Snehal B. Rao et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Received January 7, 2013; revised February 6, 2013; accepted March 6, 2013
Keywords: Euler Transform; Fox H-Function; Wright Type Hypergeometric Function; Laplace Transform; Mellin Transform; Whittaker Transform; Wright Hypergeometric Function
ABSTRACT
Let s and z be complex variables, be the Gamma function, and
for any complex
be the generalized Pochhammer symbol. Wright Type Hypergeometric Function is defined (Virchenko et al. [1]), as:
where
which is a direct generalization of classical Gauss Hypergeometric Function
. The principal aim of this paper is to study the various properties of this Wright type hypergeometric function
; which includes differentiation and integration, representation in terms of
and in terms of Mellin-Barnes type integral. Euler (Beta) transforms, Laplace transform, Mellin transform, Whittaker transform have also been obtained; along with its relationship with Fox H-function and Wright hypergeometric function.
1. Introduction and Preliminaries
The Gauss Hypergeometric Function is defined [2] as:
; and (1.1)
The Generalized Hypergeometric Function, in a classical sense has been defined [3] by
(1.2)
and no denominator parameter equal to zero or negative integer.
E. Wright [4] has further extended the generalization of the hypergeometric series in the following form
(1.3)
where and
are real positive numbers such that
When and
are equal to 1, Equation (1.3) differs from the generalized hypergeometric function
by a constant multiplier only.
The generalized form of the hypergeometric function has been investigated by Dotsenko [5], Malovichko [6] and one of the special cases considered by Dotsenko [5] as
(1.4)
and its integral representation expressed as
(1.5)
where. This is the analogue of Euler’s formula for the Gauss’s hypergeometric function [3]. In 2001 Virchenko et al. [1] defined the said Wright Type Hypergeometric Function by taking
in
(1.4) as
(1.6)
If, then (1.3) reduces to a Gauss’s hypergeometric function. Galue et al. [7] and Virchenko et al. [1] investigated some properties of the function
.
The following well-known facts have been prepared for studying various properties of the function
.
• Euler (Beta) transform (Sneddon [8]):
The Euler transform of the function is defined as
(1.7)
• Laplace transform (Sneddon [8]):
The Laplace transform of the function is defined as
(1.8)
• Mellin transform (Sneddon [8]):
The Mellin transform of the function is defined as
(1.9)
then
(1.10)
• Wright generalized hypergeometric function (Srivastava and Manocha [9]), denoted by, is defined as
(1.11)
(1.12)
where denotes the Fox H-function [10].
2. Basic Properties of the Function
Theorem 2.1
(2.1.1)
(2.1.2)
In particular,
(2.1.3)
Proof.
which is the (2.1.1).
Now,
This is the proof of (2.1.2).
For and substituting
in above result, this will immediately leads to particular case (2.1.3).
Theorem 2.2 1) If
(2.2.1)
2) If
(2.2.2)
3)
(2.2.3)
In particular,
(2.2.4)
Proof.
1)
which concludes the proof of (2.2.1).
2)
Therefore,
Which is the proof of (2.2.2).
3)
This leads the proof of (2.2.3).
On putting, in the above expression immediately leads to (2.2.4).
Theorem 2.3
If
(2.3.1)
Proof.
This establishes (2.3.1).
3. Representation of Wright Type
Hypergeometric Function in Terms of the Function
Using the definition
, and taking
we have
(3.1)
where is a
-tuple
;
is a
-tuple
.
Convergence criteria for generalized hyperfeometric function
:
1) If, the function
converges for all finite
.
2) If, the function
converges for
and diverges for
.
3) If, the function
is divergent for
.
4) If, the function
is absolutely convergent on the circle
if
.
4. Mellin-Barnes Integral Representation of
Theorem 4.1 Let
Then is represented by the MellinBarnes integral
(4.1.1)
where; the contour of integration beginning at
and ending at
, and intended to separate the poles of the integrand at
to the left and all the poles at
as well as
to the right.
Proof. We shall use the sum of residues at the poles to obtain the integral of (4.1.1).
(4.1.2)
Now,
(4.1.3)
(4.1.2) and (4.1.3) completes the proof of (4.1.1).
5. Integral Transforms of
In this section we discussed some useful integral transforms like Euler transforms, Laplace transform, Mellin transform and Whittaker transform.
Theorem 5.1 (Euler (Beta) transforms).
(5.1.1)
Proof.
This is the proof of (5.1.1).
Remark: Putting in (5.1.1), we get
(5.1.2)
Taking,
and substituting
in place of the notation
; (5.1.1) reduces to
(5.1.3)
Also, considering and
in (5.1.1), with replacement of
by
at
, we get
(5.1.4)
Theorem 5.2 (Laplace transform).
(5.2.1)
Proof.
This is the proof of (5.2.1).
Theorem 5.3 (Mellin transform).
(5.3.1)
Proof. Putting in (4.1.1), we get
(5.3.2)
where,
Using (1.9), (1.10), and (5.3.2) immediately lead to (5.3.1).
Theorem 5.4 (Whittaker transform).
(5.4.1)
Proof. To obtain Whittaker transform, we use the following integral:
where
Substituting on the L.H.S. of (5.4.1), it reduces to
This completes the proof of (5.4.1).
6. Relationship with Some Known Special Functions (Fox H-Function, Wright Hypergeometric Function)
6.1. Relationship with Fox H-Function
Using (4.1.1), we get
6.2. Relationship with Wright Hypergeometric Function
The Generalized Hypergeometric Function as in (1.3) is
(6.2.1)
From (1.11) and (6.2.1) yields
. (6.2.2)
7. Acknowledgements
The authors are thankful to the reviewers for their valuable suggestions to improve the quality of paper.
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