Few
results in connection with sum and product theorems of relative (p,q)-φ order, relative (p,q)-φ type
and relative (p,q)-φ weak type of meromorphic
functions with respect to entire functions
Tanmay Biswas
T. Biswas : Rajbari, Rabindrapalli, R. N. Tagore Road, P.O.-
Krishnagar, Dist-Nadia, PIN- 741101, West Bengal, India
[email protected]
Abstract.
Orders and types of entire and meromorphic functions have been actively
investigated by many authors. In the present paper, we aim at investigating
some basic properties in connection with sum and product of relative (p,q)-φ order, relative (p,q)-φ
type, and relative (p,q)-φ weak type of meromorphic
functions with respect to entire functions where p,q are any two positive
integers and φ : [0,+∞)→(0,+∞) be a
non-decreasing unbounded function.
Key words and phrases:
Entire function, meromorphic function, relative (p,q)-φ order, relative (p,q)-φ type, relative (p,q)-φ weak type, Property (A).
AMS Subject Classification** (2010) **: 30D20,30D30,30D35
1. Introduction, Definitions and Notations
Let f be an entire function defined in the open complex plane C. The maximum modulus function Mf(r) corresponding to f (see [12]) is defined on ∣z∣=r as Mf(r)=\QTATOPmax∣z∣=r∣f(z)∣. A non-constant entire function f is said have the
Property (A) if for any σ>1 and for all sufficiently large r, [Mf(r)]2≤Mf(rσ)
holds (see \cite[cite][\@@bibref1]). When f is meromorphic, one may
introduce another function Tf(r) known as Nevanlinna’s
characteristic function of f (see [5, p.4]), playing the same role as
Mf(r). If f is non-constant entire function, then its
Nevanlinna’s characteristic function is strictly increasing and continuous
and therefore there exists its inverse functions Tf−1(r) : (∣f(0)∣,∞) → (0,∞) with s→∞limTf−1(s)=∞.
However, throughout this paper, we assume that the reader is familiar
with the fundamental results and the standard notations of the Nevanlinna
theory of meromorphic functions which are available in [5, 9, 10, 11]
and therefore we do not explain those in details. Now we define exp[k]x=exp(exp[k−1]x) and log[k]x=log(log[k−1]x) for x∈[0,∞) and k∈N where N be the set of all positive integers. We also denote log[0]x=x, log[−1]x=expx, exp[0]x=x and exp[−1]x=logx. Further
we assume that throughout the present paper p and q always denote
positive integers.
Mainly the growth investigation of meromorphic functions has usually
been done through its Nevanlinna’s characteristic function in comparison
with those of exponential function. But if one is paying attention to
evaluate the growth rates of any meromorphic function with respect to an
entire function, the notions of relative growth indicators [8] will
come. Extending this notion, Debnath et. al. [4] introduce the
definition of relative (p,q)-th order and relative (p,q)-th lower order of a meromorphic function f with respect to
another entire function g respectively in the light of index-pair ( detail
about index-pair one may see [4, 6, 7] ). For details about it, one may
see [4]. Extending this notion, recently Biswas [2] introduce
the definitions of relative (p,q)-φ order and the
relative (p,q)-φ lower order of a meromorphic
function f with respect to another entire function g as follows:
Definition 1**.**
[2]** Let φ : [0,+∞)→(0,+∞) be a non-decreasing unbounded function. The relative (p,q)-φ order and the relative (p,q)-φ lower
order of a meromorphic function f with respect to an entire function g
are defined as
[TABLE]
If we consider φ(r)=r, then the above definition reduce to
the definitions of relative (p,q)-th order and relative (p,q)-th lower order of a meromorphic f with respect to an
entire g, introduced by Debnath et. al. [4].
If the relative (p,q)-φ order and the
relative (p,q)-φ lower order of f with respect to g are the same, then f is called a function of regular relative (p,q)-φ growth with respect to g. Otherwise, f is said
to be irregular relative (p,q)-φ growth with
respect to g.
Now in order to refine the above growth scale, one may introduce the
definitions of other growth indicators, such as relative (p,q)-φ type and relative (p,q)-φ lower type* *of entire or meromorphic functions with respect to another entire
function which are as follows:
Definition 2**.**
[2]** Let φ : [0,+∞)→(0,+∞) be a non-decreasing unbounded function. The relative (p,q)-φ type and the relative (p,q)-φ lower type
of a meromorphic function f with respect to another entire function g
having non-zero finite relative (p,q)-φ order ρg(p,q)(f,φ) are defined as :
[TABLE]
Analogously, to determine the relative growth of f having same non
zero finite relative (p,q)-φ lower order with
respect to g, one can introduce the definition of relative (p,q)-φ weak type τg(p,q)(f) and the growth indicator τg(p,q)(f) of f with respect to g of finite positive relative (p,q)-φ lower order λg(p,q)(f) in the following way:
Definition 3**.**
[2]** Let φ : [0,+∞)→(0,+∞) be a non-decreasing unbounded function. The relative (p,q)-φ weak type τg(p,q)(f,φ) and the growth indicator τg(p,q)(f,φ) of a meromorphic function f with respect to
another entire function g having non-zero finite relative (p,q)-φ lower order λg(p,q)(f,φ) are defined as :
[TABLE]
If we consider φ(r)=r, then σg(p,q)(f,r) and τg(p,q)(f,r)
are respectively known as relative (p,q)-th type and relative
(p,q)-th weak type of f with respect to g. For details
about relative (p,q)-th type, relative (p,q)-th weak type etc., one may see [3].
Here, in this paper, we aim at investigating some basic properties of
relative (p,q)-φ order, relative (p,q)-φ type and relative (p,q)-φ weak type of a
meromorphic function with respect to an entire function under somewhat
different conditions. Throughout this paper, we assume that all the growth
indicators are all nonzero finite.
2. Lemmas
In this section we present some lemmas which will be needed in the
sequel.
Lemma 1**.**
[1]** Let f be an entire function which satisfies the
Property (A) then for any positive integer n and for all sufficiently
large r,
[TABLE]
holds where δ>1.
Lemma 2**.**
[5, p. 18]** Let f be an entire function. Then for all
sufficiently large values of r,
[TABLE]
3. Main Results
In this section we present some results which will be needed in the
sequel.
Theorem 1**.**
Let f1, f2 be meromorphic functions and g1 be
any entire function such that at least f1 or f2 is of regular
relative (p,q)-φ growth with respect to g1.
Also let g1 has the Property (A). Then
[TABLE]
The equality holds when λg1(p,q)(fi,φ)>λg1(p,q)(fj,φ) with at least fj is of regular relative (p,q)-φ growth with respect to g1 where i,j=1,2 and i=j.
Proof.
The result is obvious when λg1(p,q)(f1±f2,φ)=0. So we suppose that λg1(p,q)(f1±f2,φ) > [math]. We can clearly assume that λg1(p,q)(fk,φ) is finite for k=1,2. Now let us consider that max{λg1(p,q)(f1,φ),λg1(p,q)(f2,φ)}=Δ and f2 is of regular relative (p,q)-φ growth with respect to g1.
Now for any arbitrary ε>0 from the definition of λg1(p,q)(f1,φ), we have
for a sequence values of r tending to infinity that
[TABLE]
[TABLE]
Also for any arbitrary ε>0 from the definition of ρg1(p,q)(f2,φ)(=λg1(p,q)(f2,φ)), we
obtain for all sufficiently large values of r that
[TABLE]
[TABLE]
Since Tf1±f2(r)≤Tf1(r)+Tf2(r)+O(1) for all large r, so in view of (\ref50.1) , (\ref9.1c) and Lemma 2, we obtain for a sequence values of r tending to infinity that
[TABLE]
[TABLE]
Therefore in view of Lemma 1 and Lemma 2, we
obtain from (\ref9.2) for a sequence values of r tending
to infinity and σ>1 that
[TABLE]
[TABLE]
[TABLE]
Now we get from above by letting σ→1+
[TABLE]
Since ε>0 is arbitrary,
[TABLE]
Similarly, if we consider that f1 is of regular relative (p,q)-φ growth with respect to g1 or both f1 and f2 are of regular relative (p,q)-φ growth with
respect to g1, then one can easily verify that
[TABLE]
Further without loss of any generality, let λg1(p,q)(f1,φ) < λg1(p,q)(f2,φ) and f=f1±f2. Then in
view of (\ref9.3) we get that λg1(p,q)(f,φ) ≤ λg1(p,q)(f2,φ). As, f2=±(f−f1) and in this case we obtain that λg1(p,q)(f2,φ) ≤ max{λg1(p,q)(f,φ),λg1(p,q)(f1,φ)} . As we
assume that λg1(p,q)(f1,φ) < λg1(p,q)(f2,φ), therefore we have λg1(p,q)(f2,φ) ≤ λg1(p,q)(f,φ) and hence λg1(p,q)(f,φ) = λg1(p,q)(f2,φ) = max{λg1(p,q)(f1,φ),λg1(p,q)(f2,φ)}. Therefore, λg1(p,q)(f1±f2,φ)=λg1(p,q)(fi,φ)∣i=1,2
provided λg1(p,q)(f1,φ)=λg1(p,q)(f2,φ).
Thus the theorem is established.
Theorem 2**.**
Let f1 and f2 be any two meromorphic functions and g1 be an entire function such that such that ρg1(p,q)(f1,φ) and ρg2(p,q)(f1,φ) exists . Also let g1 has the
Property (A). Then
[TABLE]
The equality holds when ρg1(p,q)(f1,φ)=ρg1(p,q)(f2,φ).
We omit the proof of Theorem 2 as it can easily be carried
out in the line of Theorem 1.
Theorem 3**.**
Let f1 be a meromorphic function and g1, g2 be
any two entire functions such that λg1(p,q)(f1,φ) and λg2(p,q)(f1,φ) exists. Also let g1±g2 has the
Property (A). Then
[TABLE]
The equality holds when λg1(p,q)(f1,φ)=λg2(p,q)(f1,φ).
Proof.
The result is obvious when λg1±g2(p,q)(f1,φ)=∞. So we suppose that λg1±g2(p,q)(f1,φ)<∞. We can clearly assume that λgk(p,q)(f1,φ) is finite for k=1,2. Further let Ψ=min{λg1(p,q)(f1,φ),λg2(p,q)(f1,φ)}. Now for any arbitrary ε>0 from the definition of λgk(p,q)(f1,φ), we have for all
sufficiently large values of r that
[TABLE]
[TABLE]
Since Tg1±g2(r)≤Tg1(r)+Tg2(r)+O(1) for all large r,, we obtain from
above and Lemma 2 for all sufficiently large values of r that
[TABLE]
[TABLE]
Therefore in view of Lemma 1 and Lemma 2, we
obtain from above for all sufficiently large values of r and any σ>1 that
[TABLE]
[TABLE]
[TABLE]
[TABLE]
As ε>0 is arbitrary, we get from above by letting σ→1+
[TABLE]
Now without loss of any generality, we may consider that λg1(p,q)(f1,φ)<λg2(p,q)(f1,φ) and g=g1±g2. Then in view of (\ref99.3) we get that λg(p,q)(f1,φ)≥λg1(p,q)(f1,φ). Further, g1=(g±g2) and in this case we obtain that λg1(p,q)(f1,φ) ≥ min{λg(p,q)(f1,φ),λg2(p,q)(f1,φ)} . As we assume that λg1(p,q)(f1,φ)<λg2(p,q)(f1,φ), therefore we have λg1(p,q)(f1,φ)≥λg(p,q)(f1,φ) and hence λg(p,q)(f1,φ)=λg1(p,q)(f1,φ)=min{λg1(p,q)(f1,φ),λg2(p,q)(f1,φ)}.
Therefore, λg1±g2(p,q)(f1,φ)=λgi(p,q)(f1,φ)∣i=1,2 provided λg1(p,q)(f1,φ)=λg2(p,q)(f1,φ). Thus the theorem follows.
Theorem 4**.**
Let f1 be a meromorphic function and g1, g2 be
any two entire functions such that f1 is of regular relative (p,q)-φ growth with respect to at least any one of g1
or g2. If g1±g2 has the Property (A), then
[TABLE]
The equality holds when ρgi(p,q)(f1,φ)<ρgj(p,q)(f1,φ) with at least f1 is of regular relative (p,q)-φ growth with respect to gj where i,j=1,2 and i=j.
We omit the proof of Theorem 4 as it can easily be carried
out in the line of Theorem 3.
Theorem 5**.**
Let f1,f2 be any two meromorphic functions and g1,
g2 be any two entire functions. Also let g1±g2 has the
Property (A). Then
[TABLE]
*when the following two conditions holds:
(i) ρgi(p,q)(f1,φ)<ρgj(p,q)(f1,φ)
with at least f1 is of regular relative (p,q)-φ
growth with respect to gj for i = 1, 2, j = 1,2 and i=j; and
(ii) ρgi(p,q)(f2,φ)<ρgj(p,q)(f2,φ)
with at least f2 is of regular relative (p,q)-φ
growth with respect to gj for i = 1, 2, j = 1,2 and i=j.
The equality holds when ρg1(p,q)(fi,φ)<ρg1(p,q)(fj,φ) and ρg2(p,q)(fi,φ)<ρg2(p,q)(fj,φ) holds simultaneously for i,1,2; j=1,2\and i=j.*
Proof.
Let the conditions (i) and (ii) of the theorem
hold. Therefore in view of Theorem 2 and Theorem 4 we get
that
[TABLE]
Since ρg1(p,q)(fi,φ)<ρg1(p,q)(fj,φ) and ρg2(p,q)(fi,φ)<ρg2(p,q)(fj,φ) hold
simultaneously for i=1,2; j=1,2\and i=j, we obtain that
[TABLE]
[TABLE]
Now in view of the conditions (i) and (ii) of the theorem, it follows from above that
[TABLE]
which is the condition for holding equality in (\ref9.xyz).
Hence the theorem follows.
Theorem 6**.**
Let f1,f2 be any two meromorphic functions and g1,
g2 be any two entire functions. Also let g1,g2 and g1±g2 satisfy the Property (A). Then
[TABLE]
*when the following two conditions holds:
(i) λg1(p,q)(fi,φ)>λg1(p,q)(fj,φ) with at least fj is of regular relative (p,q)-φ growth with respect to g1 for i = 1, 2,
j = 1,2 and i=j; and
(ii) λg2(p,q)(fi,φ)>λg2(p,q)(fj,φ) with at least fj is of regular relative (p,q)-φ growth with respect to g2 for i = 1, 2,
j = 1,2 and i=j.
The equality holds when λgi(p,q)(f1,φ)<λgj(p,q)(f1,φ) and λgi(p,q)(f2,φ)<λgj(p,q)(f2,φ) hold simultaneously for i=1,2; j=1,2\and i=j.*
Proof.
Suppose that the conditions (i) and (ii) of
the theorem holds. Therefore in view of Theorem 1 and Theorem 3, we obtain that
[TABLE]
Since λgi(p,q)(f1,φ)<λgj(p,q)(f1,φ)
and λgi(p,q)(f2,φ)<λgj(p,q)(f2,φ) holds
simultaneously for i=1,2; j=1,2\and i=j, we get that
[TABLE]
[TABLE]
Since condition (i) and (ii) of the
theorem holds, it follows from above that
[TABLE]
which is the condition for holding equality in (\ref9.xya).
Hence the theorem follows.
Theorem 7**.**
Let f1, f2 be any two meromorphic functions and g1 be any entire function such that at least f1 or f2 is of
regular relative (p,q)-φ growth with respect to g1. Also let g1 satisfy the Property (A). Then
[TABLE]
The equality holds when λg1(p,q)(fi,φ)>λg1(p,q)(fj,φ) with at least fj is of regular relative (p,q)-φ growth with respect to g1 where i,j=1,2 and i=j.
Proof.
Since Tf1⋅f2(r)≤Tf1(r)+Tf2(r) for all large r, therefore applying the same
procedure as adopted in Theorem 1 we get that
[TABLE]
Now without loss of any generality, let λg1(p,q)(f1,φ)<λg1(p,q)(f2,φ) and f=f1⋅f2. Then λg1(p,q)(f,φ)≤λg1(p,q)(f2,φ). Further, f2=f1f and Tf1(r)=Tf11(r)+O(1). Therefore Tf2(r)≤Tf(r)+Tf1(r)+O(1) and in this case we obtain that λg1(p,q)(f2,φ)≤max{λg1(p,q)(f,φ),λg1(p,q)(f1,φ)} . As we assume that λg1(p,q)(f1,φ)<λg1(p,q)(f2,φ), therefore we have λg1(p,q)(f2,φ)≤λg1(p,q)(f,φ) and hence λg1(p,q)(f,φ) = λg1(p,q)(f2,φ) = max { λg1(p,q)(f1,φ), λg1(p,q)(f2,φ) }. Therefore,
λg1(p,q)(f1⋅f2,φ)=λg1(p,q)(fi,φ)∣i=1,2 provided λg1(p,q)(f1,φ)=λg1(p,q)(f2,φ).
Hence the theorem follows.
Next we prove the result for the quotient f2f1,
provided f2f1 is meromorphic.
Theorem 8**.**
Let f1, f2 be any two meromorphic functions and g1 be any entire function such that at least f1 or f2 is of
regular relative (p,q)-φ growth with respect to g1. Also let g1 satisfy the Property (A). Then
[TABLE]
provided f2f1 is meromorphic. The equality holds when at
least f2 is of regular relative (p,q)-φ growth
with respect to g1 and λg1(p,q)(f1,φ)=λg1(p,q)(f2,φ).
Proof.
Since Tf2(r)=Tf21(r)+O(1) and Tf2f1(r)≤Tf1(r)+Tf21(r), we get
in view of Theorem 1 that
[TABLE]
Now in order to prove the equality conditions, we discuss the
following two cases:
**Case I. **Suppose f2f1(=h) satisfies
the following condition
[TABLE]
and f2 is of regular relative (p,q)-φ growth
with respect to g1.
Now if possible, let λg1(p,q)(f2f1,φ)<λg1(p,q)(f2,φ). Therefore from f1=h⋅f2 we get
that λg1(p,q)(f1,φ)=λg1(p,q)(f2,φ) which
is a contradiction. Therefore λg1(p,q)(f2f1,φ)≥λg1(p,q)(f2,φ) and in view of (\ref50.3),
we get that
[TABLE]
**Case II. ** Suppose f2f1(=h) satisfies
the following condition
[TABLE]
and f2 is of regular relative (p,q)-φ growth
with respect to g1.
Now from f1=h⋅f2 we get that either λg1(p,q)(f1,φ)≤λg1(p,q)(f2f1,φ) or
λg1(p,q)(f1,φ)≤λg1(p,q)(f2,φ). But
according to our assumption λg1(p,q)(f1,φ)≰λg1(p,q)(f2,φ). Therefore λg1(p,q)(f2f1,φ)≥λg1(p,q)(f1,φ) and in view of (\ref50.3), we get that
[TABLE]
Hence the theorem follows.
Now we state the following theorem which can easily be carried out in
the line of Theorem 7 and Theorem 8 and therefore its
proof is omitted.
Theorem 9**.**
Let f1 and f2 be any two meromorphic functions and g1 be any entire function such that such that ρg1(p,q)(f1,φ) and ρg2(p,q)(f1,φ) exists. Also let g1 satisfy
the Property (A). Then
[TABLE]
The equality holds when ρg1(p,q)(f1,φ)=ρg1(p,q)(f2,φ). Similar results hold for the quotient f2f1, provided f2f1 is meromorphic.
Theorem 10**.**
Let f1 be a meromorphic function and g1, g2 be
any two entire functions such that λg1(p,q)(f1,φ) and λg2(p,q)(f1,φ) exists. Also let g1⋅g2 satisfy
the Property (A). Then
[TABLE]
The equality holds when λgi(p,q)(f1,φ)<λgj(p,q)(f1,φ) where i,j=1,2 and i=j and gi satisfy
the Property (A). Similar results hold for the quotient g2g1, provided g2g1 is entire and satisfy the Property (A). The
equality holds when λg1(p,q)(f1,φ)=λg2(p,q)(f1,φ) and g1 satisfy the Property (A).
Proof.
Since Tg1⋅g2(r)≤Tg1(r)+Tg2(r) for all large r, therefore applying the same
procedure as adopted in Theorem 3 we get that
[TABLE]
Now without loss of any generality, we may consider that λg1(p,q)(f1,φ)<λg2(p,q)(f1,φ) and g=g1⋅g2. Then λg(p,q)(f1,φ)≥λg1(p,q)(f1,φ). Further, g1=g2g and and Tg2(r)=Tg21(r)+O(1).
Therefore Tg1(r) ≤ Tg(r) + Tg2(r) + O(1) and in this case we obtain that λg1(p,q)(f1,φ)≥min{λg(p,q)(f1,φ),λg2(p,q)(f1,φ)} . As we assume that λg1(p,q)(f1,φ)<λg2(p,q)(f1,φ), so we have λg1(p,q)(f1,φ)≥λg(p,q)(f1,φ) and hence λg(p,q)(f1,φ) = λg1(p,q)(f1,φ) = min {λg1(p,q)(f1,φ),λg2(p,q)(f1,φ)}. Therefore, λg1⋅g2(p,q)(f1,φ)=λgi(p,q)(f1,φ)∣i=1,2 provided λg1(p,q)(f1,φ)<λg2(p,q)(f1,φ)
and g1 satisfy the Property (A). Hence the first part of the theorem
follows.
Now we prove our results for the quotient g2g1,
provided g2g1 is entire and λg1(p,q)(f1,φ)=λg2(p,q)(f1,φ). Since Tg2(r)=Tg21(r)+O(1) and Tg2g1(r)≤Tg1(r)+Tg21(r), we get in view of Theorem 3 that
[TABLE]
Now in order to prove the equality conditions, we discuss the
following two cases:
**Case I. **Suppose g2g1(=h) satisfies
the following condition
[TABLE]
Now if possible, let λg2g1(p,q)(f1,φ)>λg2(p,q)(f1,φ). Therefore from g1=h⋅g2 we get that λg1(p,q)(f1,φ)=λg2(p,q)(f1,φ), which is a contradiction. Therefore λg2g1(p,q)(f1,φ)≤λg2(p,q)(f1,φ) and in
view of (\ref50.11), we get that
[TABLE]
**Case II. ** Suppose that g2g1(=h)
satisfies the following condition
[TABLE]
Therefore from g1=h⋅g2, we get that either λg1(p,q)(f1,φ)≥λg2g1(p,q)(f1,φ) or λg1(p,q)(f1,φ)≥λg2(p,q)(f1,φ). But
according to our assumption λg1(p,q)(f1,φ)λg2(p,q)(f1,φ). Therefore λg2g1(p,q)(f1,φ)≤λg1(p,q)(f1,φ) and in view of (\ref50.11), we get that
[TABLE]
Hence the theorem follows.
Theorem 11**.**
Let f1 be any meromorphic function and g1, g2
be any two entire functions such that ρg1(p,q)(f1,φ) and ρg2(p,q)(f1,φ) exists. Further let f1 is of regular
relative (p,q)-φ growth with respect to at least any
one of g1 or g2. Also let g1⋅g2 satisfy the Property
(A). Then
[TABLE]
The equality holds when ρgi(p,q)(f1,φ)<ρgj(p,q)(f1,φ) with at least f1 is of regular relative (p,q)-φ growth with respect to gj where i,j=1,2 and i=j and gi satisfy the Property (A).
Theorem 12**.**
Let f1 be any meromorphic function and g1, g2
be any two entire functions such that ρg1(p,q)(f1,φ) and ρg2(p,q)(f1,φ) exists. Further let f1 is of regular
relative (p,q)-φ growth with respect to at least any
one of g1 or g2. Then
[TABLE]
provided g2g1 is entire and satisfy the Property (A). The
equality holds when at least f1 is of regular relative (p,q)-φ growth with respect to g2, ρg1(p,q)(f1,φ)=ρg2(p,q)(f1,φ) and g1
satisfy the Property (A).
We omit the proof of Theorem 11 and Theorem 12 as
those can easily be carried out in the line of Theorem 10.
Now we state the following four theorems without their proofs as
those can easily be carried out in the line of Theorem 5 and
Theorem 6 respectively.
Theorem 13**.**
Let f1,f2 be any two meromorphic functions and g1, g2 be any two entire functions. Also let g1⋅g2 be
satisfy the Property (A). Then
[TABLE]
*when the following two conditions holds:
(i) ρgi(p,q)(f1,φ)<ρgj(p,q)(f1,φ)
with at least f1 is of regular relative (p,q)-φ
growth with respect to gj and gi satisfy the Property (A) for i = 1, 2, j = 1,2 and i=j; and
(ii) ρgi(p,q)(f2,φ)<ρgj(p,q)(f2,φ)
with at least f2 is of regular relative (p,q)-φ
growth with respect to gj and gi satisfy the Property (A) for i = 1, 2, j = 1,2 and i=j.
The quality holds when ρg1(p,q)(fi,φ)<ρg1(p,q)(fj,φ) and ρg2(p,q)(fi,φ)<ρg2(p,q)(fj,φ) holds simultaneously for i=1,2; j=1,2\and i=j.*
Theorem 14**.**
Let f1,f2 be any two meromorphic functions and g1, g2 be any two entire functions. Also let g1⋅g2, g1
and g2 be satisfy the Property (A). Then
[TABLE]
*when the following two conditions holds:
(i) λg1(p,q)(fi,φ)>λg1(p,q)(fj,φ) with at least fj is of regular relative (p,q)-φ growth with respect to g1 for i = 1, 2,
j = 1,2 and i=j; and
(ii) λg2(p,q)(fi,φ)>λg2(p,q)(fj,φ) with at least fj is of regular relative (p,q)-φ growth with respect to g2 for i = 1, 2,
j = 1,2 and i=j.
The equality holds when λgi(p,q)(f1,φ)<λgj(p,q)(f1,φ) and λgi(p,q)(f2,φ)<λgj(p,q)(f2,φ) holds simultaneously for i=1,2; j=1,2\and i=j.*
Theorem 15**.**
Let f1,f2 be any two meromorphic functions and g1, g2 be any two entire functions such that f2f1 is
meromorphic and g2g1 is entire. Also let g2g1 satisfy the Property (A). Then
[TABLE]
*when the following two conditions holds:
(i) At least f1 is of regular relative (p,q)-φ growth with respect to g2 and ρg1(p,q)(f1,φ)=ρg2(p,q)(f1,φ); and
(ii) At least f2 is of regular relative (p,q)-φ growth with respect to g2 and ρg1(p,q)(f2,φ)=ρg2(p,q)(f2,φ).
The equality holds when ρg1(p,q)(fi,φ)<ρg1(p,q)(fj,φ) and ρg2(p,q)(fi,φ)<ρg2(p,q)(fj,φ) holds simultaneously for i=1,2; j=1,2\and i=j.*
Theorem 16**.**
Let f1,f2 be any two meromorphic functions and g1, g2 be any two entire functions such that f2f1 is
meromorphic and g2g1 is entire. Also let g2g1, g1 and g2 be satisfy the Property (A). Then
[TABLE]
*when the following two conditions hold:
(i) At least f2 is of regular relative (p,q)-φ growth with respect to g1 and λg1(p,q)(f1,φ)=λg1(p,q)(f2,φ); and
(ii) At least f2 is of regular relative (p,q)-φ growth with respect to g2 and λg2(p,q)(f1,φ)=λg2(p,q)(f2,φ).
The equality holds when λgi(p,q)(f1,φ)<λgj(p,q)(f1,φ) and λgi(p,q)(f2,φ)<λgj(p,q)(f2,φ) holds simultaneously for i=1,2; j=1,2\and i=j.*
Next we intend to find out the sum and product theorems of relative (p,q)-φ type ( respectively relative (p,q)-φ lower type) and relative (p,q)-φ weak type of meromorphic function with respect to an entire
function taking into consideration of the above theorems.
Theorem 17**.**
*Let f1,f2 be any two meromorphic functions and g1, g2 be any two entire functions. Also let ρg1(p,q)(f1,φ), ρg1(p,q)(f2,φ), ρg2(p,q)(f1,φ) and ρg2(p,q)(f2,φ) are all non zero and finite.
**(A) *If ρg1(p,q)(fi,φ)>ρg1(p,q)(fj,φ)
for i, j = 1,2; i=j, and g1 has the Property (A), then
[TABLE]
(B) If ρgi(p,q)(f1,φ)<ρgj(p,q)(f1,φ)
with at least f1 is of regular relative (p,q)-φ
growth with respect to gj for i, j = 1,2; i=j and g1±g2 has the Property (A), then
[TABLE]
**(C) Assume the functions f1,f2,g1 and g2 satisfy
the following conditions:
(i) ρgi(p,q)(f1,φ)<ρgj(p,q)(f1,φ)
with at least f1 is of regular relative (p,q)-φ
growth with respect to gj for i = 1, 2, j = 1,2 and i=j;
(ii) ρgi(p,q)(f2,φ)<ρgj(p,q)(f2,φ)
with at least f2 is of regular relative (p,q)-φ
growth with respect to gj for i = 1, 2, j = 1,2 and i=j;
(iii) ρg1(p,q)(fi,φ)>ρg1(p,q)(fj,φ)
and ρg2(p,q)(fi,φ)>ρg2(p,q)(fj,φ) holds
simultaneously for i=1,2; j=1,2\and i=j;
(iv)ρgm(p,q)(fl,φ)=max[min{ρg1(p,q)(f1,φ),ρg2(p,q)(f1,φ)},min{ρg1(p,q)(f2,φ),ρg2(p,q)(f2,φ)}]∣l,m=1,2, and g1±g2 has the Property (A);
then**
[TABLE]
and
[TABLE]
Proof.
From the definition of relative (p,q)-φ type and
relative (p,q)-φ lower type of meromorphic function
with respect to an entire function, we have for all sufficiently large
values of r that
[TABLE]
[TABLE]
and for a sequence of values of r tending to infinity, we obtain that
[TABLE]
and
[TABLE]
where ε>0 is any arbitrary positive number k=1,2 and l=1,2.
Case I. Suppose that ρg1(p,q)(f1,φ)>ρg1(p,q)(f2,φ) hold. Also let ε(>0) be
arbitrary. Since Tf1±f2(r)≤Tf1(r)+Tf2(r)+O(1) for all large r, so in view of (\ref9.15), we get for all sufficiently large values of r
that
[TABLE]
[TABLE]
where A=Tg1[exp[p−1]{(σg1(p,q)(f1,φ)+ε)[log[q−1]φ(r)]ρg1(p,q)(f1,φ)}]Tg1[exp[p−1]{(σg1(p,q)(f2,φ)+ε)[log[q−1]φ(r)]ρg1(p,q)(f2,φ)}]+O(1), and in view of ρg1(p,q)(f1,φ)>ρg1(p,q)(f2,φ), and for all sufficiently large values of r, we can make the term A sufficiently small . Hence for any α=1+ε1, it follows from (\ref9.18) for all
sufficiently large values of r that
[TABLE]
[TABLE]
Hence making α→1+, we get in view of Theorem 2, ρg1(p,q)(f1,φ)>ρg1(p,q)(f2,φ) and above
for all sufficiently large values of r that
[TABLE]
[TABLE]
Now we may consider that f=f1±f2. Since ρg1(p,q)(f1,φ)>ρg1(p,q)(f2,φ) hold. Then σg1(p,q)(f,φ)=σg1(p,q)(f1±f2,φ)≤σg1(p,q)(f1,φ). Further, let f1=(f±f2). Therefore in view of Theorem 2 and ρg1(p,q)(f1,φ)>ρg1(p,q)(f2,φ), we obtain that ρg1(p,q)(f,φ)>ρg1(p,q)(f2,φ) holds. Hence in
view of (\ref9.21) σg1(p,q)(f1,φ)≤σg1(p,q)(f,φ)=σg1(p,q)(f1±f2,φ). Therefore σg1(p,q)(f,φ)=σg1(p,q)(f1,φ)⇒ σg1(p,q)(f1±f2,φ)=σg1(p,q)(f1,φ).
Similarly, if we consider ρg1(p,q)(f1,φ)<ρg1(p,q)(f2,φ), then one can easily verify that σg1(p,q)(f1±f2,φ)=σg1(p,q)(f2,φ).
Case II. Let us consider that ρg1(p,q)(f1,φ)>ρg1(p,q)(f2,φ) hold. Also let ε(>0) are
arbitrary. Since Tf1±f2(r)≤Tf1(r)+Tf2(r)+O(1) for all large r, from (\ref9.15) and (\ref9.20a), we get for a sequence
of values of r tending to infinity that
[TABLE]
[TABLE]
where B=Tg1[exp[p−1]{(σg1(p,q)(f1,φ)+ε)[log[q−1]φ(rn)]ρg1(p,q)(f1,φ)}]Tg1[exp[p−1]{(σg1(p,q)(f2,φ)+ε)[log[q−1]φ(rn)]ρg1(p,q)(f2,φ)}]+O(1), and in view
of ρg1(p,q)(f1,φ)>ρg1(p,q)(f2,φ), we can make the
term B sufficiently small by taking n sufficiently large and therefore
using the similar technique for as executed in the proof of Case I we get
from (\ref9.185) that σg1(p,q)(f1±f2,φ)=σg1(p,q)(f1,φ) when ρg1(p,q)(f1,φ)>ρg1(p,q)(f2,φ) hold. Likewise,
if we consider ρg1(p,q)(f1,φ)<ρg1(p,q)(f2,φ),
then one can easily verify that σg1(p,q)(f1±f2,φ)=σg1(p,q)(f2,φ).
Thus combining Case I and Case II, we obtain the first part of the
theorem.
Case III. Let us consider that ρg1(p,q)(f1,φ)<ρg2(p,q)(f1,φ) with at least f1 is of regular relative (p,q)-φ growth with respect to g2. We can make the term
C=Tg2[exp[p−1]{(σg2(p,q)(f1,φ)−ε)[log[q−1]φ(rn)]ρg2(p,q)(f1,φ)}]Tg2[exp[p−1]{(σg1(p,q)(f1,φ)−ε)[log[q−1]φ(rn)]ρg1(p,q)(f1,φ)}]+O(1) sufficiently
small by taking n sufficiently large, since ρg1(p,q)(f1,φ)<ρg2(p,q)(f1,φ). Hence C<ε1.
As Tg1±g2(r)≤Tg1(r)+Tg2(r)+O(1) for all large r, we get that
[TABLE]
[TABLE]
[TABLE]
Therefore for any α=1+ε1, we obtain in view of C<ε1, (\ref9.15a) and (\ref9.20) for a sequence of values of r tending to infinity that
[TABLE]
Now making α→1+, we obtain from above for a
sequence of values of r tending to infinity that
[TABLE]
Since ε>0 is arbitrary, we find that
[TABLE]
Now we may consider that g=g1±g2. Also ρg1(p,q)(f1,φ)<ρg2(p,q)(f1,φ) and at least f1 is of regular relative (p,q)-φ growth with
respect to g2. Then σg(p,q)(f1,φ)=σg1±g2(p,q)(f1,φ)≥σg1(p,q)(f1,φ). Further let g1=(g±g2).
Therefore in view of Theorem 4 and ρg1(p,q)(f1,φ)<ρg2(p,q)(f1,φ), we obtain that ρg(p,q)(f1,φ)<ρg2(p,q)(f1,φ) as at least f1 is of regular relative (p,q)-φ growth with respect to g2. Hence in view
of (\ref9.237), σg1(p,q)(f1,φ)≥σg(p,q)(f1,φ)=σg1±g2(p,q)(f1,φ). Therefore σg(p,q)(f1,φ)=σg1(p,q)(f1,φ)⇒ σg1±g2(p,q)(f1,φ)=σg1(p,q)(f1,φ).
Similarly if we consider ρg1(p,q)(f1,φ)>ρg2(p,q)(f1,φ) with at least f1 is of regular relative (p,q)-φ growth with respect to g1, then σg1±g2(p,q)(f1,φ)=σg2(p,q)(f1,φ).
**Case IV. **In this case suppose that ρg1(p,q)(f1,φ)<ρg2(p,q)(f1,φ) with at least f1 is of regular relative
(p,q)-φ growth with respect to g2. we can also
make the term D=Tg2[exp[p−1]{(σg2(p,q)(f1,φ)−ε)[log[q−1]φ(r)]ρg2(p,q)(f1,φ)}]Tg2[exp[p−1]{(σg1(p,q)(f1,φ)−ε)[log[q−1]φ(r)]ρg1(p,q)(f1,φ)}]+O(1) sufficiently small by taking r
sufficiently large as ρg1(p,q)(f1,φ)<ρg2(p,q)(f1,φ). So D<ε1 for sufficiently large r.
As Tg1±g2(r)≤Tg1(r)+Tg2(r)+O(1) for all large r, therefore from (\ref9.15a), we get for all sufficiently large values of r that
[TABLE]
[TABLE]
[TABLE]
[TABLE]
[TABLE]
and therefore using the similar technique for as executed in the proof of
Case III we get from (\ref9.238) that σg1±g2(p,q)(f1,φ)=σg1(p,q)(f1,φ)
where ρg1(p,q)(f1,φ)<ρg2(p,q)(f1,φ) and at least f1 is of regular relative (p,q)-φ growth with
respect to g2.
Likewise if we consider ρg1(p,q)(f1,φ)>ρg2(p,q)(f1,φ) with at least f1 is of regular relative (p,q)-φ growth with respect to g1, then σg1±g2(p,q)(f1,φ)=σg2(p,q)(f1,φ).
Thus combining Case III and Case IV, we obtain the second part of the
theorem.
The third part of the theorem is a natural consequence of Theorem 5 and the first part and second part of the theorem. Hence its proof is
omitted.
Theorem 18**.**
*Let f1,f2 be any two meromorphic functions and g1, g2 be any two entire functions. Also let λg1(p,q)(f1,φ), λg1(p,q)(f2,φ), λg2(p,q)(f1,φ) and λg2(p,q)(f2,φ) are all non zero and finite.
(A) If λg1(p,q)(fi,φ)>λg1(p,q)(fj,φ)
with at least fj is of regular relative (p,q)-φ
growth with respect to g1 for i, j = 1,2; i=j, and g1
has the Property (A), then*
[TABLE]
(B) If λgi(p,q)(f1,φ)<λgj(p,q)(f1,φ)
for i, j = 1,2; i=j and g1±g2 has the Property (A),
then
[TABLE]
**(C) Assume the functions f1,f2,g1 and g2 satisfy
the following conditions:
(i) ρg1(p,q)(fi,φ)>ρg1(p,q)(fj,φ)
with at least fj is of regular relative (p,q)-φ
growth with respect to g1 for i, j = 1,2 and i=j;
(ii) ρg2(p,q)(fi,φ)>ρg2(p,q)(fj,φ)
with at least fj is of regular relative (p,q)-φ
growth with respect to g2 for i, j = 1,2 and i=j;
(iii) ρgi(p,q)(f1,φ)<ρgj(p,q)(f1,φ)
and ρgi(p,q)(f2,φ)<ρgj(p,q)(f2,φ) holds
simultaneously for i, j=1,2\and i=j;
(iv)λgm(p,q)(fl,φ)=min[max{λg1(p,q)(f1,φ),λg1(p,q)(f2,φ)},max{λg2(p,q)(f1,φ),λg2(p,q)(f2,φ)}]∣l,m=1,2 and g1±g2 has the Property (A)
then we have**
[TABLE]
and
[TABLE]
Proof.
For any arbitrary positive number ε(>0), we have for all
sufficiently large values of r that
[TABLE]
[TABLE]
and for a sequence of values of r tending to infinity we obtain that
[TABLE]
and
[TABLE]
where k=1,2 and l=1,2.
Case I. Let λg1(p,q)(f1,φ)>λg1(p,q)(f2,φ) with at least f2 is of regular relative (p,q)-φ growth with respect to g1. Also let ε(>0) be arbitrary. Since Tf1±f2(r)≤Tf1(r)+Tf2(r)+O(1) for
all large r, we get from (\ref9.15x) and (\ref9.20ax), for a sequence {rn} of values of r
tending to infinity that
[TABLE]
[TABLE]
where E=Tg1[exp[p−1]{(τg1(p,q)(f1,φ)+ε)[log[q−1]φ(rn)]λg1(p,q)(f1,φ)}]Tg1[exp[p−1]{(τg1(p,q)(f2,φ)+ε)[log[q−1]φ(rn)]λg1(p,q)(f2,φ)}]+O(1) and in view of λg1(p,q)(f1)>λg1(p,q)(f2), we can make the term E sufficiently
small by taking n sufficiently large. Now with the help of Theorem 1 and using the similar technique of Case I of Theorem 17, we
get from (\ref9.18x) that
[TABLE]
Further, we may consider that f=f1±f2. Also suppose that λg1(p,q)(f1,φ)>λg1(p,q)(f2,φ) and at least f2 is of regular relative (p,q)-φ growth with
respect to g1. Then τg1(p,q)(f,φ)=τg1(p,q)(f1±f2,φ)≤τg1(p,q)(f1,φ). Now let f1=(f±f2). Therefore in view of Theorem 1, λg1(p,q)(f1,φ)>λg1(p,q)(f2,φ)
and at least f2 is of regular relative (p,q)-φ
growth with respect to g1, we obtain that λg1(p,q)(f,φ)>λg1(p,q)(f2,φ) holds. Hence in view of (\ref9.21x), τg1(p,q)(f1,φ)≤τg1(p,q)(f,φ)=τg1(p,q)(f1±f2,φ).
Therefore τg1(p,q)(f,φ)=τg1(p,q)(f1,φ)⇒ τg1(p,q)(f1±f2,φ)=τg1(p,q)(f1,φ).
Similarly, if we consider λg1(p,q)(f1,φ)<λg1(p,q)(f2,φ) with at least f1 is of regular relative (p,q)-φ growth with respect to g1 then one can easily
verify that τg1(p,q)(f1±f2,φ)=τg1(p,q)(f2,φ).
Case II. Let us consider that λg1(p,q)(f1,φ)>λg1(p,q)(f2,φ) with at least f2 is of regular relative (p,q)-φ growth with respect to g1. Also let ε(>0) be arbitrary. As Tf1±f2(r)≤Tf1(r)+Tf2(r)+O(1) for
all large r, we obtain from (\ref9.15x) for all
sufficiently large values of r that
[TABLE]
[TABLE]
where F=Tg1[exp[p−1]{(τg1(p,q)(f1,φ)+ε)[log[q−1]φ(r)]λg1(p,q)(f1,φ)}]Tg1[exp[p−1]{(τg1(p,q)(f2,φ)+ε)[log[q−1]φ(r)]λgi(p,q)(f2,φ)}]+O(1), and in view of λg1(p,q)(f1,φ)>λg1(p,q)(f2,φ), we can make the
term F sufficiently small by taking r sufficiently large and therefore
for similar reasoning of Case I we get from (\ref9.185x)
that τg1(p,q)(f1±f2,φ)=τg1(p,q)(f1,φ) when λg1(p,q)(f1,φ)>λg1(p,q)(f2,φ) and at least f2 is of regular relative (p,q)-φ growth with respect to g1.
Likewise, if we consider λg1(p,q)(f1,φ)<λg1(p,q)(f2,φ) with at least f1 is of regular relative (p,q)-φ growth with respect to g1 then one can easily
verify that τg1(p,q)(f1±f2,φ)=τg1(p,q)(f2,φ).
Thus combining Case I and Case II, we obtain the first part of the
theorem.
Case III. Let us consider that λg1(p,q)(f1,φ)<λg2(p,q)(f1,φ). Therefore we can make the term G=Tg2[exp[p−1]{(τg2(p,q)(f1,φ)−ε)[log[q−1]φ(r)]λg2(p,q)(f1,φ)}]Tg2[exp[p−1]{(τg1(p,q)(f1,φ)−ε)[log[q−1]φ(r)]λg1(p,q)(f1,φ)}]+O(1) sufficiently small by taking r sufficiently large
since λg1(p,q)(f1,φ) < λg2(p,q)(f1,φ). So
G<ε1. Since Tg1±g2(r)≤Tg1(r)+Tg2(r)+O(1) for all large r,
we get from (\ref9.15ax) for all sufficiently large values
of r that
[TABLE]
[TABLE]
[TABLE]
[TABLE]
[TABLE]
Therefore in view of Theorem 3 and using the similar
technique of Case III of Theorem 17, we get from (\ref9.236x) that
[TABLE]
Further, we may consider that g=g1±g2. As λg1(p,q)(f1,φ)<λg2(p,q)(f1,φ), so τg(p,q)(f1,φ)=τg1±g2(p,q)(f1,φ)≥τg1(p,q)(f1,φ). Further let g1=(g±g2). Therefore in view of Theorem 3
and λg1(p,q)(f1,φ)<λg2(p,q)(f1,φ) we
obtain that λg(p,q)(f1,φ)<λg2(p,q)(f1,φ) holds.
Hence in view of (\ref9.237x) τg1(p,q)(f1,φ)≥τg(p,q)(f1,φ)=τg1±g2(p,q)(f1,φ). Therefore τg(p,q)(f1,φ)=τg1(p,q)(f1,φ)⇒ τg1±g2(p,q)(f1,φ)=τg1(p,q)(f1,φ).
Likewise, if we consider that λg1(p,q)(f1,φ)>λg2(p,q)(f1,φ), then one can easily verify that τg1±g2(p,q)(f1,φ)=τg2(p,q)(f1,φ).
**Case IV. **In this case further we consider λg1(p,q)(f1,φ)<λg2(p,q)(f1,φ). Further we can make the term H=Tg2[exp[p−1]{(τg2(p,q)(f1,φ)−ε)[log[q−1]φ(rn)]λg2(p,q)(f1,φ)}]Tg2[exp[p−1]{(τg1(p,q)(f1,φ)−ε)[log[q−1]φ(rn)]λg1(p,q)(f1,φ)}]+O(1) sufficiently small by taking n
sufficiently large, since λg1(p,q)(f1,φ) < λg2(p,q)(f1,φ). Therefore H<ε1 for sufficiently
large n. As Tg1±g2(r)≤Tg1(r)+Tg2(r)+O(1) for all large r, we obtain from (\ref9.15ax) and (\ref9.20x), we obtain for
a sequence {rn} of values of r tending to infinity that
[TABLE]
[TABLE]
[TABLE]
[TABLE]
[TABLE]
and therefore using the similar technique for as executed in the proof of
Case IV of Theorem 17, we get from (\ref9.238x)
that τg1±g2(p,q)(f1,φ)=τg1(p,q)(f1,φ) when λg1(p,q)(f1,φ)<λg2(p,q)(f1,φ).
Similarly, if we consider that λg1(p,q)(f1,φ)>λg2(p,q)(f1,φ), then one can easily verify that τg1±g2(p,q)(f1,φ)=τg2(p,q)(f1,φ).
Thus combining Case III and Case IV, we obtain the second part of the
theorem.
The proof of the third part of the Theorem is omitted as it can be
carried out in view of Theorem 6 and the above cases.
In the next two theorems we reconsider the equalities in Theorem 1 to Theorem 4 under somewhat different conditions.
Theorem 19**.**
*Let f1,f2be any two meromorphic functions and g1, g2 be any two entire functions.
**(A) **The following condition is assumed to be satisfied:
(i) Either σg1(p,q)(f1,φ)=σg1(p,q)(f2,φ) or σg1(p,q)(f1,φ)=σg1(p,q)(f2,φ) holds and g1 has the
Property (A), then*
[TABLE]
**(B) The following conditions are assumed to be satisfied:
(i) Either σg1(p,q)(f1,φ)=σg2(p,q)(f1,φ) or σg1(p,q)(f1,φ)=σg2(p,q)(f1,φ) holds and g1±g2 has
the Property (A);
(ii) f1 is of regular relative (p,q)-φ growth with respect to at least any one of g1 or g2, then**
[TABLE]
Proof.
Let f1,f2,g1 and g2 be any four entire functions
satisfying the conditions of the theorem.
Case I. Suppose that ρg1(p,q)(f1,φ)=ρg1(p,q)(f2,φ) (0< ρg1(p,q)(f1,φ), ρg1(p,q)(f2,φ) <∞). Now in view of Theorem 2 it
is easy to see that ρg1(p,q)(f1±f2,φ)≤ρg1(p,q)(f1,φ)=ρg1(p,q)(f2,φ) . If possible let
[TABLE]
Let** σg1(p,q)(f1,φ)=σg1(p,q)(f2,φ).** Then in view of the first part of Theorem 17 and (\ref93.1x) we obtain that σg1(p,q)(f1,φ)=σg1(p,q)(f1±f2∓f2,φ)=σg1(p,q)(f2,φ) which is
a contradiction. Hence ρg1(p,q)(f1±f2,φ) = ρg1(p,q)(f1,φ) = ρg1(p,q)(f2,φ) . Similarly with the help of the first part of
Theorem 17, one can obtain the same conclusion under the hypothesis
σg1(p,q)(f1,φ)=σg1(p,q)(f2,φ). This proves the first part of the theorem.
**Case II. **Let us consider that ρg1(p,q)(f1,φ)=ρg2(p,q)(f1,φ) (0< ρg1(p,q)(f1,φ), ρg2(p,q)(f1,φ) <∞), f1 is of regular relative (p,q)-φ growth with respect to at least any one of g1
or g2 and (g1±g2) and g1±g2 satisfy
the Property (A). Therefore in view of Theorem 4, it follows that ρg1±g2(p,q)(f1,φ)≥ρg1(p,q)(f1,φ)=ρg2(p,q)(f1,φ) and if possible
let
[TABLE]
Let us consider that σg1(p,q)(f1,φ)=σg2(p,q)(f1,φ). Then. in view of the proof of the second part of
Theorem 17 and (\ref93.3x) we obtain that σg1(p,q)(f1,φ)=σg1±g2∓g2(p,q)(f1,φ)=σg2(p,q)(f1,φ) which is a
contradiction. Hence ρg1±g2(p,q)(f1,φ)=ρg1(p,q)(f1,φ)=ρg2(p,q)(f1,φ) . Also in view of the proof of second part of
Theorem 17 one can derive the same conclusion for the condition σg1(p,q)(f1,φ)=σg2(p,q)(f1,φ) and therefore the second part of the theorem is established.
Theorem 20**.**
*Let f1,f2 be any two meromorphic functions and g1, g2 be any two entire functions.
**(A) **The following conditions are assumed to be satisfied:
(i) (f1±f2) is of regular relative (p,q)-φ growth with respect to at least any one of g1 or g2, and g1, g2 , g1±g2 have the Property
(A);
(ii) Either σg1(p,q)(f1±f2,φ)=σg2(p,q)(f1±f2,φ) or σg1(p,q)(f1±f2,φ)=σg2(p,q)(f1±f2,φ);
(iii) Either σg1(p,q)(f1,φ)=σg1(p,q)(f2,φ) or σg1(p,q)(f1,φ)=σg1(p,q)(f2,φ);
(iv) Either σg2(p,q)(f1,φ)=σg2(p,q)(f2,φ) or σg2(p,q)(f1,φ)=σg2(p,q)(f2,φ); then*
[TABLE]
**(B) The following conditions are assumed to be satisfied:
(i) f1 and f2 are of regular relative (p,q)-φ growth with respect to at least any one of g1
or g2, and g1±g2 has the Property (A);
(ii) Either σg1±g2(p,q)(f1,φ)=σg1±g2(p,q)(f2,φ) or σg1±g2(p,q)(f1,φ)=σg1±g2(p,q)(f2,φ);
(iii) Either σg1(p,q)(f1,φ)=σg2(p,q)(f1,φ) or σg1(p,q)(f1,φ)=σg2(p,q)(f1,φ);
(iv) Either σg1(p,q)(f2,φ)=σg2(p,q)(f2,φ) or σg1(p,q)(f2,φ)=σg2(p,q)(f2,φ); then**
[TABLE]
We omit the proof of Theorem 20 as it is a natural
consequence of Theorem 19.
Theorem 21**.**
*Let f1,f2be ant two meromorphic functions and g1,g2 be any two entire functions.
(A) The following conditions are assumed to be satisfied:
(i) At least any one of f1 or f2 is of regular
relative (p,q)-φ growth with respect to g1;
(ii) Either τg1(p,q)(f1,φ)=τg1(p,q)(f2,φ) or τg1(p,q)(f1,φ)=τg1(p,q)(f2,φ) holds and g1 has the
Property (A), then*
[TABLE]
**(B) The following conditions are assumed to be satisfied:
(i) f1, g1 and g2 be any three entire
functions such that λg1(p,q)(f1,φ) and λg2(p,q)(f1,φ) exists;
(ii) Either τg1(p,q)(f1,φ)=τg2(p,q)(f1,φ) or τg1(p,q)(f1,φ)=τg2(p,q)(f1,φ) holds and g1±g2 has
the Property (A), then**
[TABLE]
Proof.
Let f1,f2,g1 and g2 be any four entire functions
satisfying the conditions of the theorem.
Case I. Let λg1(p,q)(f1,φ)=λg1(p,q)(f2,φ) (0<λg1(p,q)(f1,φ),λg1(p,q)(f2,φ)<∞) and at least f1 or f2 and (f1±f2) are of regular relative (p,q)-φ growth with respect to g1. Now, in view of Theorem 1, it is easy to see that λg1(p,q)(f1±f2,φ)≤λg1(p,q)(f1,φ)=λg1(p,q)(f2,φ). If possible let
[TABLE]
Let** τg1(p,q)(f1,φ)=τg1(p,q)(f2,φ).** Then in view of the proof of the first part of Theorem 18 and (\ref96.19xy) we obtain that τg1(p,q)(f1,φ)=τg1(p,q)(f1±f2∓f2,φ)=τg1(p,q)(f2,φ) which is a contradiction. Hence λg1(p,q)(f1±f2,φ)
= λg1(p,q)(f1,φ) =
λg1(p,q)(f2,φ) .
Similarly in view of the proof of the first part of Theorem 18 ,
one can establish the same conclusion under the hypothesis τg1(p,q)(f1,φ)=τg1(p,q)(f2,φ). This
proves the first part of the theorem.
Case II. Let us consider that λg1(p,q)(f1,φ)=λg2(p,q)(f1,φ) (0<λg1(p,q)(f1,φ),λg2(p,q)(f1,φ)<∞. Therefore in view of Theorem 3, it
follows that λg1±g2(p,q)(f1,φ)≥λg1(p,q)(f1,φ)=λg2(p,q)(f1,φ) and if possible let
[TABLE]
Suppose** τg1(p,q)(f1,φ)=τg2(p,q)(f1,φ).** Then in view of the second part of Theorem 18 and (\ref96.2t), we obtain that τg1(p,q)(f1,φ)=τg1±g2∓g2(p,q)(f1,φ)=τg2(p,q)(f1,φ) which is a
contradiction. Hence λg1±g2(p,q)(f1,φ) = λg1(p,q)(f1,φ) = λg2(p,q)(f1,φ) . Analogously with the help of the second part of
Theorem 18, the same conclusion can also be derived under the
condition τg1(p,q)(f1,φ)=τg2(p,q)(f1,φ) and therefore the second part of the theorem is
established.
Theorem 22**.**
*Let f1,f2be any two meromorphic functions and g1, g2 be any two entire functions.
(A) The following conditions are assumed to be satisfied:
(i) At least any one of f1 or f2 is of regular
relative (p,q)-φ growth with respect to g1 and g2. Also g1, g2, g1±g2 have satisfy the Property
(A);
(ii) Either τg1(p,q)(f1±f2,φ)=τg2(p,q)(f1±f2,φ) or τg1(p,q)(f1±f2,φ)=τg2(p,q)(f1±f2,φ);
(iii) Either τg1(p,q)(f1,φ)=τg1(p,q)(f2,φ) or τg1(p,q)(f1,φ)=τg1(p,q)(f2,φ);
(iv) Either τg2(p,q)(f1,φ)=τg2(p,q)(f2,φ) or τg2(p,q)(f1,φ)=τg2(p,q)(f2,φ); then*
[TABLE]
**(B) The following conditions are assumed to be satisfied:
(i) At least any one of f1 or f2 are of regular
relative (p,q)-φ growth with respect to g1±g2, and g1±g2 has satisfy the Property (A);
(ii) Either τg1±g2(p,q)(f1,φ)=τg1±g2(p,q)(f2,φ) or τg1±g2(p,q)(f1,φ)=τg1±g2(p,q)(f2,φ) holds;
(iii) Either τg1(p,q)(f1,φ)=τg2(p,q)(f1,φ) or τg1(p,q)(f1,φ)=τg2(p,q)(f1,φ) holds;
(iv) Either τg1(p,q)(f2,φ)=τg2(p,q)(f2,φ) or τg1(p,q)(f2,φ)=τg2(p,q)(f2,φ) holds, then**
[TABLE]
We omit the proof of Theorem 22 as it is a natural
consequence of Theorem 21.
Theorem 23**.**
*Let f1,f2 be any two meromorphic functions and g1, g2 be any two entire functions. Also let ρg1(p,q)(f1,φ), ρg1(p,q)(f2,φ), ρg2(p,q)(f1,φ) and ρg2(p,q)(f2,φ) are all non zero and finite.
(A) Assume the functions f1,f2 and g1 satisfy the
following conditions:
(i) ρg1(p,q)(fi,φ)>ρg1(p,q)(fj,φ)
for i, j = 1,2 and i=j;
(ii) g1 satisfies the Property (A), then*
[TABLE]
Similarly,
[TABLE]
*holds provided (i) f2f1 is meromorphic, (ii) ρg1(p,q)(fi,φ) > ρg1(p,q)(fj,φ) ∣ i, 1,2; j = 1,2; i = j and (iii) g1 satisfy the Property (A).
**(B) **Assume the functions g1,g2 and f1 satisfy the
following conditions:
(i) ρgi(p,q)(f1,φ)<ρgj(p,q)(f1,φ)
with at least f1 is of regular relative (p,q)-φ
growth with respect to gj for i, j = 1,2 and i=j, and gi satisfy the Property (A);
(ii) g1⋅g2 satisfy the Property (A), then*
[TABLE]
Similarly,
[TABLE]
*holds provided (i) g2g1 is entire and
satisfy the Property (A), (ii) At least f1 is of regular
relative (p,q)-φ growth with respect to g2, (iii) ρgi(p,q)(f1,φ)<ρgj(p,q)(f1,φ) ∣ i = 1,2; j = 1,2; i = j and (iv)
g1 satisfy the Property (A).
(C) Assume the functions f1,f2, g1 and g2 satisfy
the following conditions:
(i) g1⋅g2 satisfy the Property (A);
(ii) ρgi(p,q)(f1,φ)<ρgj(p,q)(f1,φ)
with at least f1 is of regular relative (p,q)-φ
growth with respect to gj for i = 1, 2, j = 1,2 and i=j;
(iii) ρgi(p,q)(f2,φ)<ρgj(p,q)(f2,φ)
with at least f2 is of regular relative (p,q)-φ
growth with respect to gj for i = 1, 2, j = 1,2 and i=j;
(iv) ρg1(p,q)(fi,φ)>ρg1(p,q)(fj,φ)
and ρg2(p,q)(fi,φ)>ρg2(p,q)(fj,φ) holds
simultaneously for i=1,2; j=1,2\and i=j;
(v) ρgm(p,q)(fl,φ)=max[min{ρg1(p,q)(f1,φ),ρg2(p,q)(f1,φ)},min{ρg1(p,q)(f2,φ),ρg2(p,q)(f2,φ)}]∣l,m=1,2; then*
[TABLE]
Similarly,
[TABLE]
*holds provided f2f1 is meromorphic function and g2g1 is entire function which satisfy the following conditions:
(i) g2g1 satisfy the Property (A);
(ii) At least f1 is of regular relative (p,q)-φ growth with respect to g2 and ρg1(p,q)(f1,φ)=ρg2(p,q)(f1,φ);
(iii) At least f2 is of regular relative (p,q)-φ growth with respect to g2 and ρg1(p,q)(f2,φ)=ρg2(p,q)(f2,φ);
(iv) ρg1(p,q)(fi,φ)<ρg1(p,q)(fj,φ)
and ρg2(p,q)(fi,φ)<ρg2(p,q)(fj,φ) holds
simultaneously for i=1,2; j=1,2\and i=j;
(v) ρgm(p,q)(fl,φ)=max[min{ρg1(p,q)(f1,φ),ρg2(p,q)(f1,φ)},min{ρg1(p,q)(f2,φ),ρg2(p,q)(f2,φ)}]∣l,m=1,2.*
Proof.
Let us suppose that ρg1(p,q)(f1,φ), ρg1(p,q)(f2,φ), ρg2(p,q)(f1,φ) and ρg2(p,q)(f2,φ) are all non
zero and finite.
Case I. Suppose that ρg1(p,q)(f1,φ)>ρg1(p,q)(f2,φ). Also let g1 satisfy the Property (A). Since Tf1⋅f2(r)≤Tf1(r)+Tf2(r) for all large r, therefore applying the same
procedure as adopted in Case I of Theorem 17 we get that
[TABLE]
Further without loss of any generality, let f=f1⋅f2 and ρg1(p,q)(f2,φ) < ρg1(p,q)(f1,φ) = ρg1(p,q)(f,φ). Then in view of (\ref77.3), we obtain that σg1(p,q)(f,φ) = σg1(p,q)(f1⋅f2,φ) ≤ σg1(p,q)(f1,φ). Also f1=f2f and Tf2(r) = Tf21(r) + O(1). Therefore Tf1(r)≤Tf(r)+Tf2(r)+O(1) and in this case also
we obtain from (\ref77.3) that σg1(p,q)(f1,φ) ≤ σg1(p,q)(f,φ) = σg1(p,q)(f1⋅f2,φ). Hence σg1(p,q)(f,φ) = σg1(p,q)(f1,φ) ⇒ σg1(p,q)(f1⋅f2,φ)
= σg1(p,q)(f1,φ).
Similarly, if we consider ρg1(p,q)(f1,φ)<ρg1(p,q)(f2,φ), then one can verify that σg1(p,q)(f1⋅f2,φ) = σg1(p,q)(f2,φ).
Next we may suppose that f=f2f1 with f1, f2
and f are all meromorphic functions.
Sub Case IA. Let ρg1(p,q)(f2,φ) < ρg1(p,q)(f1,φ). Therefore in view of Theorem 9, ρg1(p,q)(f2,φ) <
ρg1(p,q)(f1,φ) = ρg1(p,q)(f,φ). We have f1=f⋅f2. So, σg1(p,q)(f1,φ) = σg1(p,q)(f,φ) = σg1(p,q)(f2f1,φ).
**Sub Case IB. **Let ρg1(p,q)(f2,φ) > ρg1(p,q)(f1,φ). Therefore in view of Theorem 9, ρg1(p,q)(f1,φ) <
ρg1(p,q)(f2,φ) = ρg1(p,q)(f,φ). Since Tf(r)=Tf1(r)+O(1)=Tf1f2(r)+O(1), So σg1(p,q)(f2f1,φ) = σg1(p,q)(f2,φ).
**Case II. **Let ρg1(p,q)(f1,φ)>ρg1(p,q)(f2,φ). Also let g1 satisfy the Property (A). As Tf1⋅f2(r)≤Tf1(r)+Tf2(r) for all large r, therefore applying the same
procedure as explored in Case II of Theorem 17, one can easily
verify that σg1(p,q)(f1⋅f2,φ)=σg1(p,q)(f1,φ) and σg1(p,q)(f2f1,φ) =
σg1(p,q)(fi,φ)∣i=1,2 under the conditions specified in the theorem.
Similarly, if we consider ρg1(p,q)(f1,φ)<ρg1(p,q)(f2,φ), then one can verify that σg1(p,q)(f1⋅f2,φ) = σg1(p,q)(f2,φ)
and σg1(p,q)(f2f1,φ) = σg1(p,q)(f2,φ).
Therefore the first part of theorem follows from Case I and Case
II.
**Case III. **Let g1⋅g2 satisfy the Property (A) and ρg1(p,q)(f1,φ)<ρg2(p,q)(f1,φ) with at least f1 is of regular relative (p,q)-φ growth with
respect to g2. Since Tg1⋅g2(r)≤Tg1(r)+Tg2(r) for all large r,
therefore applying the same procedure as adopted in Case III of Theorem 17 we get that
[TABLE]
Further without loss of any generality, let g=g1⋅g2 and ρg(p,q)(f1,φ) = ρg1(p,q)(f1,φ) < ρg2(p,q)(f1,φ). Then in view of
(\ref7.6j), we obtain that σg(p,q)(f1,φ) = σg1⋅g2(p,q)(f1,φ) ≥ σg1(p,q)(f1,φ). Also g1=g2g and
Tg2(r) = Tg21(r) + O(1). Therefore Tg1(r)≤Tg(r)+Tg2(r)+O(1) and in this case we obtain from (\ref7.6j) that σg1(p,q)(f1,φ) ≥ σg(p,q)(f1,φ) = σg1⋅g2(p,q)(f1,φ). Hence σg(p,q)(f1,φ) = σg1(p,q)(f1,φ) ⇒ σg1⋅g2(p,q)(f1,φ) = σg1(p,q)(f1,φ).
Similarly, if we consider ρg1(p,q)(f1,φ)>ρg2(p,q)(f1,φ) with at least f1 is of regular relative (p,q)-φ growth with respect to g1, then one can verify
that σg1⋅g2(p,q)(f1,φ) = σg2(p,q)(f1,φ).
Next we may suppose that g=g2g1 with g1, g2, g are all entire functions satisfying the conditions specified in
the theorem.
Sub Case IIIA. Let ρg1(p,q)(f1,φ) < ρg2(p,q)(f1,φ). Therefore in view of Theorem 12, ρg(p,q)(f1,φ) = ρg1(p,q)(f1,φ) < ρg2(p,q)(f1,φ). We have g1=g⋅g2. So σg1(p,q)(f1,φ) = σg(p,q)(f1,φ) =σg2g1(p,q)(f1,φ).
**Sub Case IIIB. **Let ρg1(p,q)(f1,φ) > ρg2(p,q)(f1,φ). Therefore in view of Theorem 12, ρg(p,q)(f1,φ) = ρg2(p,q)(f1,φ) < ρg1(p,q)(f1,φ). Since Tg(r)=Tg1(r)+O(1)=Tg1g2(r)+O(1), So σg2g1(p,q)(f1,φ) = σg2(p,q)(f1,φ).
**Case IV. **Suppose g1⋅g2 satisfy the Property (A). Also
let ρg1(p,q)(f1,φ)<ρg2(p,q)(f1,φ) with at least f1 is of regular relative (p,q)-φ growth with
respect to g2. As Tg1⋅g2(r)≤Tg1(r)+Tg2(r) for all large r, the
same procedure as explored in Case IV of Theorem 17, one can easily
verify that σg1⋅g2(p,q)(f1,φ) = σg1(p,q)(f1,φ) and σg2g1(p,q)(f1,φ) = σgi(p,q)(f1,φ)∣i=1,2 under the conditions specified in the theorem.
Likewise, if we consider ρg1(p,q)(f1,φ)>ρg2(p,q)(f1,φ) with at least f1 is of regular relative (p,q)-φ growth with respect to g1, then one can verify
that σg1⋅g2(p,q)(f1,φ) = σg2(p,q)(f1,φ) and σg2g1(p,q)(f1,φ) = σg2(p,q)(f1,φ). Therefore the
second part of theorem follows from Case III and Case IV.
Proof of the third part of the Theorem is omitted as it can be
carried out in view of Theorem 13 and Theorem 15 and the
above cases.
Theorem 24**.**
*Let f1,f2 be any two meromorphic functions and g1, g2 be any two entire functions. Also let λg1(p,q)(f1,φ), λg1(p,q)(f2,φ), λg2(p,q)(f1,φ) and λg2(p,q)(f2,φ) are all non zero and finite.
(A) Assume the functions f1,f2 and g1 satisfy the
following conditions:
(i) λg1(p,q)(fi,φ)>λg1(p,q)(fj,φ) with at least fj is of regular relative (p,q)-φ growth with respect to g1 for i, j = 1,2
and i=j;
(ii) g1 satisfy the Property (A), then*
[TABLE]
Similarly,
[TABLE]
*holds provided f2f1 is meromorphic, at least f2 is of
regular relative (p,q)-φ growth with respect to g1 where g1 satisfy the Property (A) and λg1(p,q)(fi,φ) > λg1(p,q)(fj,φ) ∣ i = 1,2; j = 1,2; i = j.
**(B) **Assume the functions g1,g2 and f1 satisfy the
following conditions:
(i) λgi(p,q)(f1,φ)<λgj(p,q)(f1,φ) for i, j = 1,2, i=j; and gi
satisfy the Property (A)
(ii) g1⋅g2 satisfy the Property (A), then*
[TABLE]
Similarly,
[TABLE]
*holds provided g2g1 is entire and satisfy the Property (A),
g1 satisfy the Property (A) and λgi(p,q)(f1,φ)<λgj(p,q)(f1,φ) ∣ i = 1,2; j = 1,2; i = j.
(C) Assume the functions f1,f2, g1 and g2 satisfy
the following conditions:
(i) g1⋅g2, g1 and g2 are satisfy the
Property (A);
(ii) λg1(p,q)(fi,φ)>λg1(p,q)(fj,φ) with at least fj is of regular relative (p,q)-φ growth with respect to g1 for i = 1, 2,
j = 1,2 and i=j;
(iii) λg2(p,q)(fi,φ)>λg2(p,q)(fj,φ) with at least fj is of regular relative (p,q)-φ growth with respect to g2 for i = 1, 2,
j = 1,2 and i=j;
(iv) λgi(p,q)(f1,φ)<λgj(p,q)(f1,φ) and λgi(p,q)(f2,φ)<λgj(p,q)(f2,φ) holds simultaneously for i=1,2; j=1,2\and i=j;
(v) λgm(p,q)(fl,φ)=min[max{λg1(p,q)(f1,φ),λg1(p,q)(f2,φ)},max{λg2(p,q)(f1,φ),λg2(p,q)(f2,φ)}]∣l,m=1,2; then*
[TABLE]
Similarly,
[TABLE]
*holds provided f2f1 is meromorphic and g2g1
is entire functions which satisfy the following conditions:
(i) g2g1, g1 and g2 satisfy the
Property (A);
(ii) At least f2 is of regular relative (p,q)-φ growth with respect to g1 and λg1(p,q)(f1,φ)=λg1(p,q)(f2,φ);
(iii) At least f2 is of regular relative (p,q)-φ growth with respect to g2 and λg2(p,q)(f1,φ)=λg2(p,q)(f2,φ);
(iv) λgi(p,q)(f1,φ)<λgj(p,q)(f1,φ) and λgi(p,q)(f2,φ)<λgj(p,q)(f2,φ) holds simultaneously for i=1,2; j=1,2\and i=j;
(v) λgm(p,q)(fl,φ)=min[max{λg1(p,q)(f1,φ),λg1(p,q)(f2,φ)},max{λg2(p,q)(f1,φ),λg2(p,q)(f2,φ)}]∣l,m=1,2.*
Proof.
Let us consider that λg1(p,q)(f1,φ), λg1(p,q)(f2,φ), λg2(p,q)(f1,φ) and λg2(p,q)(f2,φ) are all non zero and finite.
Case I. Suppose λg1(p,q)(f1,φ)>λg1(p,q)(f2,φ)
with at least f2 is of regular relative (p,q)-φ
growth with respect to g1 and g1 satisfy the Property (A). Since Tf1⋅f2(r)≤Tf1(r)+Tf2(r) for all large r, therefore applying the same
procedure as adopted in Case I of Theorem 18 we get that
[TABLE]
Further without loss of any generality, let f=f1⋅f2 and λg1(p,q)(f2,φ) < λg1(p,q)(f1,φ) = λg1(p,q)(f,φ). Then in
view of (\ref77.90), we obtain that τg1(p,q)(f,φ) = τg1(p,q)(f1⋅f2,φ) ≤ τg1(p,q)(f1,φ). Also f1=f2f and
Tf2(r) = Tf21(r) + O(1). Therefore Tf1(r)≤Tf(r)+Tf2(r)+O(1) and in this case we obtain from the above
arguments that τg1(p,q)(f1,φ) ≤ τg1(p,q)(f,φ) = τg1(p,q)(f1⋅f2,φ). Hence τg1(p,q)(f,φ) = τg1(p,q)(f1,φ) ⇒ τg1(p,q)(f1⋅f2,φ) = τg1(p,q)(f1,φ).
Similarly, if we consider λg1(p,q)(f1,φ)<λg1(p,q)(f2,φ) with at least f1 is of regular relative (p,q)-φ growth with respect to g1, then one can easily
verify that τg1(p,q)(f1⋅f2,φ) = τg1(p,q)(f2,φ).
Next we may suppose that f=f2f1 with f1, f2
and f are all meromorphic functions satisfying the conditions specified in
the theorem.
Sub Case IA. Let λg1(p,q)(f2,φ) <λ g1(p,q)(f1,φ). Therefore in view of Theorem 8, λg1(p,q)(f2,φ) < λg1(p,q)(f1,φ) = λg1(p,q)(f,φ). We
have f1=f⋅f2. So τg1(p,q)(f1,φ) = τg1(p,q)(f,φ) = τg1(p,q)(f2f1,φ).
**Sub Case IB. **Let λg1(p,q)(f2,φ) > λg1(p,q)(f1,φ). Therefore in view of Theorem 8, λg1(p,q)(f1,φ) < λg1(p,q)(f2,φ) = λg1(p,q)(f,φ). Since Tf(r)=Tf1(r)+O(1)=Tf1f2(r)+O(1), So τg1(p,q)(f2f1,φ) = τg1(p,q)(f2,φ).
**Case II. **Let λg1(p,q)(f1,φ)>λg1(p,q)(f2,φ) with at least f2 is of regular relative (p,q)-φ growth with respect to g1 where g1 satisfy
the Property (A). As Tf1⋅f2(r)≤Tf1(r)+Tf2(r) for all large r, so
applying the same procedure as adopted in Case II of Theorem 18 we
can easily verify that τg1(p,q)(f1⋅f2,φ)=τg1(p,q)(f1,φ) and τg2g1(p,q)(f1,φ)=τgi(p,q)(f1,φ)∣i=1,2
under the conditions specified in the theorem.
Similarly, if we consider λg1(p,q)(f1,φ)<λg1(p,q)(f2,φ) with at least f1 is of regular relative (p,q)-φ growth with respect to g1, then one can easily
verify that τg1(p,q)(f1⋅f2,φ) = τg1(p,q)(f2,φ).
Therefore the first part of theorem follows Case I and Case II.
**Case III. **Let λg1(p,q)(f1,φ)<λg2(p,q)(f1,φ) and g1⋅g2 satisfy the Property
(A).Since Tg1⋅g2(r)≤Tg1(r)+Tg2(r) for all large r, therefore applying the same
procedure as adopted in Case III of Theorem 18 we get that
[TABLE]
Further without loss of any generality, let g=g1⋅g2 and λg(p,q)(f1,φ) = λg1(p,q)(f1,φ) < λg2(p,q)(f1,φ). Then in view of
(\ref79.0), we obtain that τg(p,q)(f1,φ) = τg1⋅g2(p,q)(f1,φ) ≥ τg1(p,q)(f1,φ). Also g1=g2g and
Tg2(r) = Tg21(r) + O(1). Therefore Tg1(r)≤Tg(r)+Tg2(r)+O(1) and in this case we obtain from above
arguments that τg1(p,q)(f1,φ) ≥ τg(p,q)(f1,φ) = τg1⋅g2(p,q)(f1,φ). Hence τg(p,q)(f1,φ) = τg1(p,q)(f1,φ) ⇒ τg1⋅g2(p,q)(f1,φ) = τg1(p,q)(f1,φ).
If λg1(p,q)(f1,φ)>λg2(p,q)(f1,φ), then
one can easily verify that τg1⋅g2(p,q)(f1,φ) = τg2(p,q)(f1,φ).
Next we may suppose that g=g2g1 with g1, g2, g are all entire functions satisfying the conditions specified in
the theorem.
Sub Case IIIA. Let λg1(p,q)(f1,φ) < λg2(p,q)(f1,φ). Therefore in view of Theorem 10, λg(p,q)(f1,φ) =
λg1(p,q)(f1,φ) < λg2(p,q)(f1,φ). We have
g1=g⋅g2. So τg1(p,q)(f1,φ) = τg(p,q)(f1,φ) =τg2g1(p,q)(f1,φ).
**Sub Case IIIB. **Let λg1(p,q)(f1,φ) > λg2(p,q)(f1,φ). Therefore in view of Theorem 10, λg(p,q)(f1,φ) =
λg2(p,q)(f1,φ) < λg1(p,q)(f1,φ). Since Tg(r)=Tg1(r)+O(1)=Tg1g2(r)+O(1), So τg2g1(p,q)(f1,φ) = τg2(p,q)(f1,φ).
**Case IV. **Suppose λg1(p,q)(f1,φ)<λg2(p,q)(f1,φ) and g1⋅g2 satisfy the Property (A).
Since Tg1⋅g2(r)≤Tg1(r)+Tg2(r) for all large r, then adopting the same
procedure as of Case IV of Theorem 18, we obtain that τg1⋅g2(p,q)(f1,φ)=τg1(p,q)(f1,φ)
and τg2g1(p,q)(f1,φ)=τgi(p,q)(f1,φ)∣i=1,2.
Similarly if we consider that λg1(p,q)(f1,φ)>λg2(p,q)(f1,φ), then one can easily verify that τg1⋅g2(p,q)(f1,φ) = τg2(p,q)(f1,φ).
Therefore the second part of the theorem follows from Case III and
Case IV.
Proof of the third part of the Theorem is omitted as it can be
carried out in view of Theorem 14 , Theorem 16 and the
above cases.
Theorem 25**.**
*Let f1,f2 be any two meromorphic functions and g1, g2 be any two entire functions.
(A) The following condition is assumed to be satisfied:
(i) Either σg1(p,q)(f1,φ)=σg1(p,q)(f2,φ) or σg1(p,q)(f1,φ)=σg1(p,q)(f2,φ) holds;
(ii) g1 satisfies the Property (A), then*
[TABLE]
**(B) The following conditions are assumed to be satisfied:
(i) Either σg1(p,q)(f1,φ)=σg2(p,q)(f1,φ) or σg1(p,q)(f1,φ)=σg2(p,q)(f1,φ) holds;
(ii) f1 is of regular relative (p,q)-φ growth with respect to at least any one of g1 or g2.
Also g1⋅g2 satisfy the Property (A). Then we have**
[TABLE]
Proof.
Let f1,f2 be any two meromorphic functions and g1, g2 be
any two entire functions satisfying the conditions of the theorem.
Case I. Suppose that ρg1(p,q)(f1,φ)=ρg1(p,q)(f2,φ) (0<ρg1(p,q)(f1,φ),ρg1(p,q)(f2,φ)<∞) and g1 satisfy the Property (A). Now
in view of Theorem 9, it is easy to see that ρg1(p,q)(f1⋅f2,φ)≤ρg1(p,q)(f1,φ)=ρg1(p,q)(f2,φ). If possible let
[TABLE]
Let** σg1(p,q)(f1,φ)=σg1(p,q)(f2,φ).** Now in view of the first part of Theorem 23
and (\ref20.1) we obtain that σg1(p,q)(f1,φ)=σg1(p,q)(f2f1⋅f2,φ)=σg1(p,q)(f2,φ) which is a
contradiction. Hence ρg1(p,q)(f1⋅f2,φ) = ρg1(p,q)(f1,φ) = ρg1(p,q)(f2,φ). Similarly with the help of the first part of
Theorem 23, one can obtain the same conclusion under the hypothesis
σg1(p,q)(f1,φ)=σg1(p,q)(f2,φ). This prove the first part of the theorem.
Case II. Let us consider that ρg1(p,q)(f1,φ)=ρg2(p,q)(f1,φ) (0<ρg1(p,q)(f1,φ),ρg2(p,q)(f1,φ)<∞), f1 is of regular relative (p,q)-φ growth with respect to at least any one of g1
or g2. Also g1⋅g2 satisfy the Property (A). Therefore in
view of Theorem 11, it follows that ρg1⋅g2(p,q)(f1,φ)≥ρg1(p,q)(f1,φ)=ρg2(p,q)(f1,φ) and if possible
let
[TABLE]
Further suppose that** σg1(p,q)(f1,φ)=σg2(p,q)(f1,φ).** Therefore in view of the proof of the
second part of Theorem 23 and (\ref20.2), we
obtain that σg1(p,q)(f1,φ) = σg2g1⋅g2(p,q)(f1,φ) = σg2(p,q)(f1,φ) which is a contradiction. Hence ρg1⋅g2(p,q)(f1,φ) = ρg1(p,q)(f1,φ) = ρg2(p,q)(f1,φ) . Likewise in
view of the proof of second part of Theorem 23, one can obtain the
same conclusion under the hypothesis σg1(p,q)(f1,φ)=σg2(p,q)(f1,φ). This proves the
second part of the theorem.
Theorem 26**.**
*Let f1,f2 be any two meromorphic functions and g1, g2 be any two entire functions.
**(A) **The following conditions are assumed to be satisfied:
(i) (f1⋅f2) is of regular relative (p,q)-φ growth with respect to at least any one g1 or g2;
(ii) (g1⋅g2), g1 and g2
all satisfy the Property (A);
(iii) Either σg1(p,q)(f1⋅f2,φ)=σg2(p,q)(f1⋅f2,φ) or σg1(p,q)(f1⋅f2,φ)=σg2(p,q)(f1⋅f2,φ);
(iv) Either σg1(p,q)(f1,φ)=σg1(p,q)(f2,φ) or σg1(p,q)(f1,φ)=σg1(p,q)(f2,φ);
(v) Either σg2(p,q)(f1,φ)=σg2(p,q)(f2,φ) or σg2(p,q)(f1,φ)=σg2(p,q)(f2,φ); then*
[TABLE]
**(B) The following conditions are assumed to be satisfied:
(i) (g1⋅g2) satisfy the Property
(A);
(ii) f1 and f2 are of regular relative (p,q)-φ growth with respect to at least any one g1 or g2;
(iii) Either σg1⋅g2(p,q)(f1,φ)=σg1⋅g2(p,q)(f2,φ) or σg1⋅g2(p,q)(f1,φ)=σg1⋅g2(p,q)(f2,φ);
(iv) Either σg1(p,q)(f1,φ)=σg2(p,q)(f1,φ) or σg1(p,q)(f1,φ)=σg2(p,q)(f1,φ);
(v) Either σg1(p,q)(f2,φ)=σg2(p,q)(f2,φ) or σg1(p,q)(f2,φ)=σg2(p,q)(f2,φ); then**
[TABLE]
We omit the proof of Theorem 26 as it is a natural
consequence of Theorem 25.
Theorem 27**.**
*Let f1,f2 be any two meromorphic functions and g1, g2 be any two entire functions.
(A) The following conditions are assumed to be satisfied:
(i) At least any one of f1 or f2 are of regular
relative (p,q)-φ growth with respect to g1;
(ii) Either τg1(p,q)(f1,φ)=τg1(p,q)(f2,φ) or τg1(p,q)(f1,φ)=τg1(p,q)(f2,φ) holds.
(iii) g1 satisfy the Property (A), then*
[TABLE]
**(B) The following conditions are assumed to be satisfied:
(i) f1 be any meromorphic function and g1, g2
be any two entire functions such that λg1(p,q)(f1,φ) and λg2(p,q)(f1,φ) exist and g1⋅g2 satisfy the
Property (A);
(ii) Either τg1(p,q)(f1,φ)=τg2(p,q)(f1,φ) or τg1(p,q)(f1,φ)=τg2(p,q)(f1,φ) holds, then**
[TABLE]
Proof.
Let f1,f2 be any two meromorphic functions and g1, g2 be
any two entire functions satisfy the conditions of the theorem.
Case I. Let λg1(p,q)(f1,φ)=λg1(p,q)(f2,φ) (0<λg1(p,q)(f1,φ),λg1(p,q)(f2,φ)<∞), g1 satisfy the Property (A) and at
least f1 or f2 is of regular relative (p,q)-φ growth with respect to g1. Now in view of Theorem 7
it is easy to see that λg1(p,q)(f1⋅f2,φ) ≤ λg1(p,q)(f1,φ) = λg1(p,q)(f2,φ). If possible let
[TABLE]
Also let** τg1(p,q)(f1,φ)=τg1(p,q)(f2,φ).** Then in view of the proof of first part of Theorem 24 and (\ref20.3), we obtain that τg1(p,q)(f1,φ)=τg1(p,q)(f2f1⋅f2,φ)=τg1(p,q)(f2,φ)
which is a contradiction. Hence λg1(p,q)(f1⋅f2,φ) = λg1(p,q)(f1,φ) = λg1(p,q)(f2,φ). Analogously, in view of the proof of first
part of Theorem 24, one can derived the same conclusion under the
hypothesis τg1(p,q)(f1,φ)=τg1(p,q)(f2,φ). Hence the first part of the theorem is
established.
Case II. Let us consider that λg1(p,q)(f1,φ)=λg2(p,q)(f1,φ) (0<λg1(p,q)(f1,φ),λg2(p,q)(f1,φ)<∞ and g1⋅g2 satisfy the Property
(A). Therefore in view of Theorem 10, it follows that λg1⋅g2(p,q)(f1,φ) ≥ λg1(p,q)(f1,φ) = λg2(p,q)(f1,φ) and if
possible let
[TABLE]
Further let** τg1(p,q)(f1,φ)=τg2(p,q)(f1,φ).** Then in view of second part of Theorem 24
and (\ref20.4), we obtain that τg1(p,q)(f1,φ)=τg2g1⋅g2(p,q)(f1,φ)=τg2(p,q)(f1,φ) which is a
contradiction. Hence λg1⋅g2(p,q)(f1,φ) = λg1(p,q)(f1,φ) = λg2(p,q)(f1,φ). Similarly by second part of Theorem 24, we
get the same conclusion when τg1(p,q)(f1,φ)=τg2(p,q)(f1,φ) and therefore the second part of
the theorem follows.
Theorem 28**.**
*Let f1,f2 be any two meromorphic functions and g1, g2 be any two entire functions.
(A) The following conditions are assumed to be satisfied:
(i) g1⋅g2, g1 and g2 satisfy the
Property (A);
(ii) At least any one of f1 or f2 are of regular
relative (p,q)-φ growth with respect to g1 and g2;
(iii) Either τg1(p,q)(f1⋅f2,φ)=τg2(p,q)(f1⋅f2,φ) or τg1(p,q)(f1⋅f2,φ)=τg2(p,q)(f1⋅f2,φ);
(iv) Either τg1(p,q)(f1,φ)=τg1(p,q)(f2,φ) or τg1(p,q)(f1,φ)=τg1(p,q)(f2,φ);
(v) Either τg2(p,q)(f1,φ)=τg2(p,q)(f2,φ) or τg2(p,q)(f1,φ)=τg2(p,q)(f2,φ); then*
[TABLE]
**(B) The following conditions are assumed to be satisfied:
(i) g1⋅g2 satisfy the Property (A);
(ii) At least any one of f1 or f2 are of regular
relative (p,q)-φ growth with respect to g1⋅g2;
(iii) Either τg1⋅g2(p,q)(f1,φ)=τg1⋅g2(p,q)(f2,φ) or τg1⋅g2(p,q)(f1,φ)=τg1⋅g2(p,q)(f2,φ) holds;
(iv) Either τg1(p,q)(f1,φ)=τg2(p,q)(f1,φ) or τg1(p,q)(f1,φ)=τg2(p,q)(f1,φ) holds;
(v) Either τg1(p,q)(f2,φ)=τg2(p,q)(f2,φ) or τg1(p,q)(f2,φ)=τg2(p,q)(f2,φ) holds, then**
[TABLE]
We omit the proof of Theorem 28 as it is a natural
consequence of Theorem 27.
Remark 1**.**
If we take f2f1 instead of f1⋅f2 and g2g1 instead of g1⋅g2 where f2f1 is
meromorphic and g2g1 is entire function, and the other
conditions of Theorem 25, Theorem 26, Theorem 27
and Theorem 28 remain the same, then conclusion of Theorem 25, Theorem 26, Theorem 27 and Theorem 28
remains valid.