ON NIL-SYMMETRIC RINGS AND MODULES SKEWED BY RING ENDOMORPHISM
Ibrahim Adnan Mustafa 1,* , Chenar Abdulkareem Ahmed 1
1 Department of Mathematics, College of Science, University of Zakho, Zakho, Kurdistan Region, Iraq
*Corresponding author email: ibrahim.mustafa@uoz.edu.krd
Received: 24 Feb 2025 Accepted: 23 May 2025 Published: 20 Aug 2025 https://doi.org/10.25271/sjuoz.2025.13.3.1492
The symmetric property plays an important
role in non-commutative ring theory and module theory. In this paper, we study
the symmetric property with one element of the ring and two nilpotent elements of
skewed by ring endomorphism
on rings, introducing the concept of a right
-
-symmetric ring and
extend the concept of right
-
-symmetric rings to
modules by introducing another concept called the right
-
-symmetric module which
is a generalization of
-symmetric modules.
According to this, we examine the characterization of a right
-
-symmetric ring and a
right
-
-symmetric module and their related properties including ring
and explore their connections to other classes of rings and modules. Furthermore,
we investigate the concept of
-
-symmetric on some ring extensions
and localizations like
Dorroh extension, Jordan extension and module localizations like
.
KEYWORDS: Reduced-Ring, Symmetric Ring, Flat Module, -Reduced
Module, Polynomial Module.
Every ring in this study has a
unique identity, and every module that is investigated is a unital module. and
denotes the ring
of integers, integers modulo
and the set of
nilpotent elements in
, respectively. Furthermore,
denote the
identity endomorphism, an endomorphism of an arbitrary ring
(For short, endo)
and right
-module
respectively.
is the left
annihilator of
in
.
A ring is reduced (For
short red-ring), if it has no nonzero nilpotent elements. However, if
implies
for
, then endo
of the ring
is said to be rigid
(For short,
-ring endo) (Krempa, 1996). If there is a
-ring endo
of ring
, then
is said to be
-rigid ring (For
short,
-
-ring) (Suarez H., et al., 2024). Note that,
-
-rings are red-rings
by [(Hong et al., 2000),
Proposition 5]. and any
-ring endo
of a ring is a monomorphism. Cohn introduced a
ring
as reversible, if
whenever
, then
, for
. Lembek referred
to a ring
as symmetric (For
short,
-ring), if
whenever
, then
for
According to [(Shin, 1973), Lemma 1.1], every red-ring
is symmetric; however, the convers does not true in general [(Anderson & Camillo, 1999), Example 11.5]. Although, it
is clear that
-rings are reversible and commutative rings are symmetric, the
convers of each of them does not true in general [(Anderson & Camillo, 1999), Example 1.5
and 11.5] and [(Marks, 2002), Example 5 and 7]. As
an extension of
-rings and a
specific instance of
-semi-commutative rings, Chakraborty
and Das presented the idea of
-symmetric rings in (Chakraborty & Das, 2014). A ring
is right(R) (left(L))
-symmetric (For
short, R(L)-
-ring), if for
and
then
. A ring is
-ring if it is both
L(R)
-ring.
The concept of an -symmetric ring was first proposed
by Kwak, T. K. in 2007, as an extension of
-rings and a
generalization of
-
rings. In (Kwak, 2007) an endo
of a ring
is called L(R)-
-symmetric ring(For
short,
-
-ring), if
imply
for
A ring
is L(R)-
-
-ring if there
exists a L(R)-
-ring endo
of
the
concepts of an
-
-ring is an
extension of
-rings and
it is also a generalization of
-
rings.
The ring notion was recently extended to include
modules. A module is called
symmetric (For short,
-module), if
whenever
satisfy
then we have
((Lambek, 1971) and (Raphael, 1975)). A module
is
-semi-commutative
if,
implies
for
. The module
is semi-commutative
if it is
-semi-commutative.
Buhphang and Rege in (Buhphang & Rege, 2002) examined
the fundamental characteristics of semi-commutative modules. Agayev and
Harmanci concentrated on semi-commutativity of subrings of matrix rings and
carried out additional research on semi-commutative rings and modules in (Agayev & Harmancı, 2007).
Motivated to the above, this article
is structured to introduce and define a new kind of rings named a R--
-
ring as a
generalization of
-
-rings and an
extension of
-rings, and to
explore and provide various characterizations, features and relations about
this concept and to study its related properties. Additionally, we investigate
the concept of right
-
-symmetric on some
of ring extensions and localizations. This leads to a number of
well-known outcomes as corollaries of our results. Then we
extend the property of R-
-
rings to modules
by introducing the notion of right
-
-symmetric module
which is a generalization of
-symmetric modules
and extensions of symmetric modules. We examine the characteristics of
right
-
-symmetric modules and their
associated attributes, such as localizations and module extensions.
On -
-Symmetric Rings:
The fundamental structure of -
-
rings is examined in this section,
along with a number of associated ring features. We begin with
the following definition.
Definition 2.1 An endo of a ring
is said to be left(L)-right(R)
-
-symmetric(For
short, L-R-
-
-ring), if whenever
for
and
A ring
is L-R-
-
if there exists a L-R
endo
of
. Moreover,
is
-
-ring if it is both
L-R-
-
-
-ring.
Remark 2.2:
1.
A ring is
-ring if
is
-
-symmetric, where
is the identity endo.
2.
Every subring with
of an
-
-ring is also
-
-ring.
3.
, but the converse
does not true (See (Kwak, 2007)Example 2.7(1) ).
4.
The concept of -
-ring is not R-L-
-
-ring through the
following example.
Example 2.3 Suppose
that a ring then
(i)
Let be an endo
defined by:
If for
then we get
and so
since
is commutative.
This yields
and hence
is R-
-
-ring. For
with
we have
and thus
is not L-
-
-ring.
(ii) Let be an endo
defined by:
By using the same technique as in (i), we may demonstrate
that is L-
-
-
-ring. However,
is not R-
-
-
-ring for
but
and thus
is not R-
-
-
-ring.
Lemma 2.4
(1) For a ring ,
is R-
-
-ring if and only
if
for
and
.
(2) Consider be a reversible
ring.
is R-
-
-ring if and
only if
is L-
-
-ring.
Proof. (1) It suffices to show that for
and
implies
, when
is right
-
-ring. Let
, then
for
,
and
, and hence
by the condition. Thus
(2) Let for
. If
is R-
-
-ring, then
since
is reversible, we
have
and hence
is L-
-
-ring. The converse
is similar.
The condition "is reversible" in (Proposition
2.4) is irremovable, as demonstrated by Example 2.3.
While it is evident that all
-symmetric objects are
-
-ring, the
following example shows that the converse is not true.
Example 2.5 Assume
is the ring of
integer modulo
and
Using the
standard addition and multiplication. Since
is
-
-ring. Now let
be defined by
. Then, for
but
and thus
is not an
-
-ring.
Consider is a ring and
,
is called the L-annihilator
of
in
. If
, then we write
instead of
Lemma 2.6 For a ring , then the following are equivalent
for a nonzero endo
:
(1) is R-
-
-ring;
(2) for any
and
;
if and only if
for any
and
;
(4) for any
and
Proof. (1) (3). Suppose that
for
and
For any
Then
and hence
Therefore
The converse is obvious. (1) (2) and (3)
(4) is clear.
Lemma 2.7 The class of -
-rings is
closed under direct products.
Proof. Note that and
for each
Now, let
,where
Thus for
and
Since
is R-
-
-ring for each
, then
for each
So we get
Therefore, the
direct product
of
is R-
-
-ring.
Recently, it was proven that if such that
(
), then
is R(L)
reversible, and the ring
is called R(L)
-reversible if there
exist a R(L) reversible endo
of
A ring
is
-reversible (Başer et al., 2009) if
it is both L(R)
-reversible.
Theorem 2.8 Let
be a
-
-ring. Then we have
the following.
1.For , then
and
Consequently,
is right
-reversible ring.
2.Consider is a monomorphism
of
Then we have the
following.
i. is
-symmetric ring,
ii.For then
and
Conversely, if
or
for some
then
Proof. The proof is similar to that
of [(Kwak, 2007), Theorem2.5].
EXTENSIONS OF RIGHT -
-SYMMETRIC RINGS
:
In this section, we investigate the properly of
right -
-symmetric on some
extensions of right
-
-symmetric. One may
ask whether the following extensions
are right
-
-symmetric, if
is right
-
-symmetric.
According to this, many results were obtained. Consider
an
upper triangular matrix ring,
matrix ring over
, denoted as
. Suppose that
represents the subring of
where all diagonal entries are the
same.
For any red-ring , both
and
qualify as R-
-
-rings for
any given endo
. However, the following
counterexample demonstrates that there exists a red-ring
with an endo
such that
does not satisfy the R-
-
-rings condition.
Example 3.1
An automorphism of
defined by:
and
Assume Now for
and
we have
but
Therefore,
is not
-
-ring.
The trivial extension of a ring by a
-bimodule
is the ring
, which can be obtained by the
standard addition and multiplication as follows:
This is isomorphic to the ring the usual matrix
operations are used. For an endo
of a ring
and the trivial
extension
of
defined by:
is an endo of . Since
is isomorphic to
The trivial extension of the red-ring is symmetric by [(Huh et al., 2005), corollary
2.4]. However, for a R--
-ring
.
need not be a
right
-
-ring by the following
example.
Example 3.2 Suppose
the R--
-ring
. Assume
be an endo
defined by
. Take
Let
but
Thus
is not right
-
-ring.
Proposition 3.3 Consider is a red-ring,
then
is a R-
-
-ring.
Proof. The proof is similar to that
of [(Kwak, 2007), Proposition3.2].
The following is an extension of the trivial extension of the
-
ring to a new ring:
And,
The endo defined by
is further extended to an endo
of a ring
for any
. If
is
-
then
is not a R-
-
-ring by [(Kwak, 2007), Example 3.4]. The following
example shows that
cannot be
-
-ring for any
even if
is an
-
ring.
Example 3.4 Consider
is an endo of an
-
ring
. Note that
for
By [(Hong et al., 2000),
Proposition 5] In particular
Let for
But we have,
Thus is not a R-
-
-ring.
Theorem 3.5 Consider
is a red-ring and
. If
is a R-
-
-ring with
then
is a R-
-
-ring, where
is the ideal
generated by
Proof. Suppose
If
then
If
, then
is a right
-
-ring by
Proposition 3.3, Now for
the prove is
similar to the proof of [(Kwak, 2007), Theorem 3.8].
From (Harmanci et al., 2021),
Consider is a ring and
a subring of
and
. The operations of the ring
are twice addition
and multiplication. We provide sufficient and necessary criteria for
to be
-
-ring in the
following proposition.
Proposition 3.6 Consider is a ring and
is a subring of
Then the following
are equivalent:
is R-
-
-ring;
(2) is R-
-
-ring.
Proof. (1) (2) Let
with
Let
,
and
By(1),
in
. Hence
and so
is R-
-
-ring,
(2) (1) Assume that
and
with
Then all
components of
and
are nilpotent in
Since
is R-
-
-ring, we obtain
Hence
is R-
-
-ring.
The polynomial ring over a right -symmetric is now
examined to see if it is a R-
-
-ring.
However, the following example shows that the answer is
negative.
Example 3.7 Assume that is the field of
integers modulo 2, and consider
is the free
algebra of polynomials with zero constant term in non-commuting intermediates
and
over
Define an
automorphism
of
by :
Take an ideal in the ring
generated by the
following elements:
and
where
Now is symmetric by [(Huh et al., 2005),Example
3.1] and so a R-
-
ring. By [(Mohammadi et al., 2012),
Example 3.6],
we have
. Now
but
because
Hence
is not a R-
-
-ring.
According to Rege and Chhawchharia (Rege&Chhawchharia,1997),a ring Armendariz exists if whenever any polynomials
satisfy
then
for each
and
.
Since Armendariz was the first to demonstrate that a
red‑ring always satisfies this criterion, they used this
terminology ([(Armendariz, 1974), Lemma1]). Assume is a ring with an endo
Recall that the
map
by
.
Proposition 3.8 Suppose is an Armendariz
ring then
is R-
-
-ring if and only
if
is a R-
-
-ring.
Proof. It also suffices to establish
necessity. Let with
and so
for all
and
.
since
is Armendariz and
a R-
-
-ring. This yields
therefore,
is a R-
-
-ring.
Theorem 3.9 (1)
For a ring
is
-
then
is a R-
-
-ring.
(2)
If the skew polynomial ring
of a ring
is a
-ring, then
is a
-
-ring.
Proof. (1) Consider is
-
. Note that any
-
ring is reduced
and
is a monomorphism
by [(Marks, 2002), P.218]. We show that
is R-
-
-ring. Assume
for
Then we obtain
since
is reduced (and so
symmetric). Thus,
Since
is
-
,
and thus
is a R-
-
-ring.
(2) Assume for
. Let
Then
since
is
-ring, we get
and so
Thus
is a R-
-
-ring.
The Dorroh extension(For short DoEx)
of an algebra over a commutative
ring
, introduced by
Dorroh in 1932(Dorroh, 1932), is a construction that
enlarges
by incorporating
elements of
. It is defined as
the Abelian group
with
multiplication given by
for all
and
. This operation
preserves the algebraic structure while introducing a direct interaction
between elements of
and
. Additionally, any
-linear endo
of
extends naturally
to an 𝑆, S-algebra homomorphism
, defined by
, applying
to the first
component while keeping the second component fixed.
Theorem 3.10 Consider is an algebra
equipped with an endo
and an identity
element, defined over a commutative red-ring
. Then
is a R-
-
-ring if and only
if the DoEx
of
by
is R-
-
-ring.
Proof. It is clear that . Since
is a commutative red-ring.
Consider
and
with
Thus
Since
is
-
-ring, we get
So
Thus
is
-
-ring.
SOME LOCALIZATIONS OF RIGHT -
-SYMMETRIC RINGS:
Assume that is a monomorphism of the ring
. The construction of an over-ring
of
( A ring
is an over ring of
integral domain
if
is a subring of
and
is a subring of
the field of fraction
the relationship
As introduced by Jordan, is now
under consideration (for more details, see (Jordan, 1982)). Define
as the subset of
the skew Laurent polynomial ring
consisting of
elements of the form
for
and
Notably, for
the relation
hold for any
This implies that
for any
the transformation
follows the pattern:
From this, it follows that forms a subring of
equipped with the
natural operation:
And,
and
Notably, serves as an
over-ring of
and the mapping
defined by
is an automorphism
of
Jordan established that such an extension always exists for
any given pair
(Jordan, 1982).
This is achieved using left localization of
the skew polynomial with respect to
the set of powers of
This extension
is commonly
referred to as the Jordan extension of
by
Proposition 4.1 Consider is a ring with a
monomorphism, then
is R-
-
-ring if and only
if the Jordan extension
is R-
-
-ring.
Proof. If is R-
-
-ring, then so is each
subring
with
Therefore,
it is enough to demonstrate the necessity. Assume
is
-
-ring and
where
for
Then
and
. From
we get
and so
by assumption. Hence
.
Therefore, Jordan extension is right
-
-ring.
Recall that the map defined by
is an endo of
and the map
obviously extends
Proposition 4.2 If is an Armendariz ring, then the
following claims are equivalent:
(1) is a R-
-
-ring;
(2) is a R-
-
-ring;
(3) is a R-
-
-ring.
Proof. (1) is proven in
proposition 3.8
(2) Showing necessity
is sufficient. Let
with
Then
such that
and so
Since
is R-
-
-ring, we obtain
Hence
Thus
is a R-
-
-ring.
(3) and (3)
are
clear.
Proposition 4.3 Assume that is a ring and that
is an infinite subring with all of
its nonzero elements regular in
. Then
is R-
-
-ring if and only
if
is R-
-
-ring if and only
if
is R-
-
-ring.
Proof. It is sufficient to
demonstrate that, is
-
-ring when
so is
,
is obtained as the subdirect product
of an infinite collection of copies of
, as
comprises an infinite subring where
each nonzero element is regular in
according
to the hypothesis. Thus
is
-
-ring because
is
-
-ring by the
assumption.
ON RIGHT -
-SYMMETRIC
MODULES:
This section extends the idea of a R--
-ring to modules by
introducing the notion of a right
-
-symmetric module,
which is an extension of symmetric modules and generalization of
-symmetric modules.
Some of the well-established results which are obtained
in section 3 and section 4 are generalized to right
-
-symmetric modules.
We introduce the following definition first.
Definition 5.1 Assume is a ring and
a nonzero endo
of
. An
-module
is called a right
-
-symmetric modules (For
short R-
-
-module) if
whenever
for
and
implies
Example 5.2:
1.
R--
-symmetric modules
are exactly R-
-
-module.
2.
For any commutative ring,
any module is an
-
-modules.
3.
Let be a division
ring,
and
. Then
is an
-
-module.
4.
It is clear that -symmetric modules
are
-
-module but the
converse implication is not true as we see in the following example.
Example 5.3 Let
be the ring of
integers. We now consider the ring
and the
-module
and
an homomorphism
defined on
by
where
.
is R-
-
-module for
and
where
,
we have,
Also,
But is not
-symmetric for
,
, we have,
But,
However, the converse is true if, is an
-
-module by the
following Lemma.
Lemma 5.4 Let
be an
-
-module, then the
following are equivalent:
1.
is an
-symmetric module;
2.
is an
-
symmetric module.
Proof. (1) (2) It is clear.
(2) (1) Let
for
and
. If
, is trivial. Then
implies
since
is
-
symmetric. Hence
and since
is an
-
-module implies
that
Therefore,
is an
-
-module and by [(Agayev et al., 2009), Theorem
2.1]
is an
-symmetric
module.
Proposition 5.5 For a given endo of a ring and an
-module
. The statements
below are equivalent:
1.
is R-
-
-module,
2.
for any
if and only if
for
and
4.
for any
and
Proof. (1) (3) Suppose that
for
and
Then
for any
and
and hence
Therefore
and
. The converse is clear.
(1)
(2) and (3)
(4) is obvious
Proposition 5.6 Suppose that is a ring and
an endo of
and
-module. Then we
have the following:
implies
for each
permutation
of the set
where
and
.
if and only if
for any
Proof. The proof is similar to the proof of
[(Agayev et al., 2009), Proposition2.4].
Proposition 5.7 Suppose is a ring and
an endo of
and
-module
Then we have the
following:
1.
The class of a R--
-modules is closed
under submodules, and direct sums.
2.
The direct product of R--
-modules is R-
-
-module.
3.
If is a central
idempotent of a ring
with
and
, then
and
are R-
-
-module if and only
if
is right
-
-module.
Proof. (1) Depending on the definitions and algebraic structures, the proof is straightforward.
(2) Note that and
for each
. Suppose that
is
-
-module for each
and let
where,
and
Then
for each
and
by hypothesis
since
and
for each
This implies
entailing that the
direct product
is R-
-
-module.
(3) Establishing necessity is enough.
Assume and
are R-
-
-modules. Consider
, for
, and
, then
And
By hypothesis, we
get
and
,
and
and
is a R-
-
-module.
According to (Lee & Zhou, 2004), the module is said to be
-reduced, if for each
and each
with
Lemma 5.8 ([(Raphael, 1975), Lemma 1.2]). Let be an
-module. Then the following
statements are equivalent:
1.
is
-reduced;
2.
The following statements are true:
For each and
If the module is 1-red-module, it is referred to
as reduced. Hence, a ring
is a red-ring if
and only if
is is
1-red-module as an
-module
.
Proposition 5.9
Every -reduced module is
a R-
-
-module.
Proof. Consider and
with
we prove
We apply
conditions of
-reduced module in
the process. Now
Then,
Hence
is a R-
-
-module.
The following illustration shows that, in general, Proposition 5.9's converse is not true.
Example 5.10 Consider denote the ring of
integer modulo 4. Let the ring
and the
-module
and a homomorphism
is defined by
.
is R-
-
-module but not
-reduced.
For, if and
Then
but
. Hence
is not
-reduced.
Proposition 5.11 For a ring and
-module
. Then the
following conditions are equivalent,
i.
is R-
-
-module.
ii.
Each submodule of is R-
-
-module.
iii.
Each finitely generated
submodule of is
-
-module.
iv.
Each cyclic submodule of is R-
-
-module.
Proof. It is a direct result of definitions and Proposition 3.6.
Theorem 5.12 Every flat module over an R--
-ring is an R-
-
-module.
Proof. Assume be a flat module
over the R-
-
-ring
and
a short exact sequence with
free
-module. By [(Lee & Zhou, 2004), Theorem 2.3] is a R-
-
-module and we
write
and any element
for
Let
where
and
Since
is flat there
exists a homomorphism
such that
Now set
Then
Since
is R-
-
-module,
. Then
. Since
we have
Therefore
Therefore
is R-
-
-module.
Proposition 5.13 Assume are rings and
be a ring endo.
If
is a right
-module, then
is a right
-module via
for all
and
is R-
-
-module, if and
only if
is R-
-
-module.
Proof. Let be an R-
-
-module. Consider
and
Such that
Then
Since
is R-
-
-module, we have,
Hence is a
-
-module.
Conversely. Assume that is onto and
is a R-
-
-module. Let
and
such that
. Since
is onto, there
exists
such that
and
Then
Since
is right
-
-module, we have
Hence
Thus
is R-
-
-module.
Now we study the -symmetric property
on some module extensions and module localizations like
,
,
The following concepts were introduced by Lee and Zhou. For a module , We examine
is an Abelian
group under clearly addition operation. Additionally, the next, scalar
product operation turns
into a right
-module:
For and
becomes a right module over
as a result of these operations. In the same way, the Laurent polynomial extension
becomes a right
module over
with a similar
scalar product. Zhou and Lee (Lee & Zhou, 2004) also introduced
notations for
module as,
. Each of the above
is abelian group underneath the addition condition. Furthermore,
is a module for
under the product
operation as:
In the same way, the skew Laurent
polynomial module transforms into a
module on
Again, from (Lee & Zhou, 2004), module is known as
-Armendariz if
the below conditions holds: (i) For
and
for the case if
(ii) any
and
imply
for all
and
And then,
Anderson and Camillo (Anderson & Camillo, 1999),
extended the concept of Armendariz ring to Armendariz module, as follows: A
-module
is Armendariz when,
if
and
such that
implies
for all
and
. The Armendariz property
is applicable for any finite product of polynomials. Clearly,
is an Armendariz
ring if and only if
is an Armendariz
-module.
Theorem 5.14 Consider is a
-Armendariz module.
Then, the statements that follow are equivalent:
1.
is R-
-
-module;
2.
is R-
-
-module;
3.
is R-
-
-module.
Proof. It suffices to demonstrate
that 1 3. Let
and
. Then we obtain
Let
this implies
for all
. Thus, by
hypothesis
. Therefore
and so
is a R-
-
-module.
Corollary 5.15 Consider be an Armendariz
module. Then the following are equivalent:
1.
is R-
-
-module;
2.
is R-
-
-module;
3.
is R-
-
-module.
Proposition 5.16 Consider is an endo
of a ring
and
is
-reduced module.
Then
is R-
-
-module over
if and only if
is R-
-
-module over
for integer
Proof. Let is right
-
-module with
where
. Note that
for each
and
with
Therefore,
it is sufficient to display the cases
Since
The
following equations are available to us:
(1)
(3)
Since is
-reduced for any
and each
-reduced module is
semi-commutative. These facts are used as follows:
Eq(1) and Eq(2) gives
and so
and
multiplying by
gives
so we have,
and
From Eq(1),(2) and
(3)
we get
and,
in a similar way. If
we multiply the right side of Eq(3) by
and
respectively, then
we obtain
and
in turn
Inductively we assume that
where
We apply the above
method to Eq
. First, the
induction hypotheses and Eq
give
and,
If we multiply Eq on the right side
by
and
respectively, then
we obtain
and so
In turn. This
shows that
for all
and
with
Consequently,
for all
and
with
and thus
by [(Kwak, 2007), Theorem 2.5(1)]. This
yields
and therefore
is R-
-
-module.
If implies
for
, then an element
of a ring
is right regular. Regular indicates
that it is both left and right regular (and so not a zero divisor), while left
regular is defined similarly. Assume that
is a subset of
that is multiplicatively closed and
made up of central regular elements. Let
be an automorphism
of
and consider
Then
in
and the induced
map
defined by
is also an
automorphism.
Proposition 5.17 Consider a ring and a subset
of
that is
multiplicatively closed and consists of central regular elements. Then
(1) is a R-
-
-ring if and only
if is
is a R-
-
-ring.
(2)
A module is R-
-
-module if and only
if
is a R-
-
-module.
Proof.(1) Assume with
and
Since
is included in the centre of
we have and so
for some
But
is R-
-
-ring by the
condition, so
and
Hence
is R-
-
-ring.
(2) Since a submodule of a R--
-module is
likewise a R-
-
-module, it
is sufficient to verify the required condition. Assume that
is a R-
-
-module and
for
and
where
. Since
is included in the centre of
, we have
and so
By assumption
. Therefore
Hence
is a R-
-
-module.
Corollary 5.18 (1) For a ring is R-
-
-ring if and only
if is
a R-
-
-ring.
(2) For a -module
,
is R-
-
-module if and only if
is a R-
-
-module.
Proof (1). Consider Then clearly
is a
multiplicatively closed subset of
. Since
it follows that
is right
-
-ring by proposition 5.17(1).
(2) It is evident from proposition 5.17(2). if . Then
is a
multiplicatively closed subset of
consisting of
regular central element of
. Since
and
is a classical
right quotient for
if every regular
element of
is invertible in
and every element
of
can be written in
the form a
with
and
regular.
A right Ore ring is a ring where, for any
with
being regular,
with
also regular, such
that
It is well known that
is a right ore ring if and only if its classical right quotient ring
exists. Now,
suppose
is a ring with the
classical right quotient ring
Then any
automorphism
of
extends to
by defining
its action on fractions as
for all
provided that
remains regular
whenever
is a regular
element in
Theorem 5.19 Consider is Ore ring
with an endo
of
and
the classical right
quotient ring
ring of
. Then
(1) is a R-
-
-ring if and only
if
is a R-
-
-ring.
(2)
is a R-
-
-module if and only
if
is a R-
-
-module.
Proof. (1) Consider is a R-
-
-ring. Assume
and
with
where
and
with
regular. Let
be an
ring Then
is
and so
with
regular such that
and
Now
with
regular such that
. Hence
Let
and
be the ideals in
, generated by
and
within
, respectively.
Then each of
and
are
with
Since
is right Ore, for
with
regular such that
.Here note that
Indeed,
and so
So
Similarly, also there exists and
with
regular such that
Thus, we obtain
that
and hence
This implies
and
So we have
It follows that
since
is a R-
-
-ring.
Similar, there exists and
with
regular such that
and,
Form
We have
and hence
It follows that,
and hence
Now we have
therefore
is a R-
-
-ring.
(2) Assume that is a R-
-
-module. Let
and
with
where
and
with
regular. Let
be an
ring Then
is
and so
then
with
regular such that
and
Now
with
regular such that
. Hence
Let
and
be the ideals in
, generated by
and
within
, respectively. Then
each of
and
are
with
and
Since
is right Ore, for
with
regular such that
.Here note that
Indeed,
and so
So
Similarly, also
and
with
regular such that
Thus, we obtain
that
and hence
This implies
and
So we have
It follows that
since
is a R-
-
-module.
Similar, and
with
regular such that
and,
Form
We have
and hence
It follows that,
and hence
Now we have
therefore
is a R-
-
-module.
CONCLUSION
This article introduced the concept
right -
symmetric rings
and then extends it to right
-
symmetric modules,
which serve as generalizations of both
-symmetric rings
and
-symmetric modules.
Several results were founded as the characterization of
-
-symmetric rings in
section 2, also for
-
-symmetric modules
in section 5. In addition to that we investigated the concept of an
-
-symmetric rings on
some of ring extensions and localizations in section 3 and 4, also for
-
-symmetric modules
in section. As a proposal for a future work, the following questions are
presented;
1. Are all right -
-symmetric rings
and
-
-symmetric modules necessarily
non-commutative?
2. Is there a relationship between -
-symmetric module
and
-semi-commutative?
3.Are there a class of modules which are -symmetric over
their endomorphism?
Acknowledgments:
The authors would like to express their sincere gratitude to the Department of Mathematics, College of Science, University of Zakho, for providing a supportive research environment. The constructive feedback from anonymous reviewers is also gratefully acknowledged, as it significantly contributed to the improvement of this manuscript.
Author Contributions:
Ibrahim A. Mustafa conceptualized the study and drafted the initial version of the manuscript. Chenar A. Ahmed contributed to the development of the theoretical framework, reviewed the manuscript critically, and assisted in its final revision. Both authors read and approved the final version of the manuscript.
Declaration:
The authors declare that there are no known financial or personal conflicts of interest that could have appeared to influence the work reported in this paper. The manuscript has not been published elsewhere and is not under consideration by any other journal.
Funding:
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
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