1. Introduction
In this article, we will use the symbols
R to denote a ring and
Z to denote a center of
The anticommutator of elements
a and
b, given by
will be denoted as
while the commutator,
will be represented by
where
a and
b belong to a ring
A ring
R is deemed prime if, for every
in
the equality
implies that either
a or
b is equal to zero. A derivation on
R is defined as an additive mapping
that satisfies the property
for every
a and
b in
Let
be a fixed element in
and let
be a mapping that satisfies the equality
for every
a in
In this case,
is said to be an inner derivation of
R induced by
otherwise, it is an outer derivation of
An antiautomorphism of
R is an additive bijective map
that adheres to the condition
for every
a and
b in
If
for every
a in
then
is known as an involution, denoted by
Within a ring with the involution
an element
a is classified as hermitian if
or skew-hermitian if
The involution is categorized as the second-kind if the intersection of
Z with the set of all skew-hermitian elements is non-zero; otherwise, it is referred to as the first kind. For more comprehensive information about the above concepts, refer to the books [
1] (Chapters I & VII) and [
2,
3].
Example 1. - (1)
Any involution ∗ can be regarded as an antiautomorphism Λ satisfying implying that Λ is the involution itself. However, it should be noted that not all antiautomorphisms are involutions, as demonstrated in
- (2)
Consider a real quaternion ring, and a mapping Λ from to itself defined as where represents the conjugate of In other words, if where for then χ can be expressed as However, it should be noted that Λ does not possess an order of one or two, indicating that it is not an involution.
A classical problem in ring theory revolves around investigating and establishing conditions that lead to the commutativity of a ring
Over time, researchers have discovered that derivations of rings and their modules are among the most effective tools for addressing this problem. Extensive literature suggest a close connection between the overall structure of a ring
R and the behavior of additive maps defined on
R (see [
4]). Consequently, considerable interest has been devoted to exploring the relationship between the commutativity of a prime ring
R and the behavior of certain special mappings on
Many authors have examined the commutativity of semiprime and prime rings, studying constrained maps like automorphisms, derivations, and centralizers that operate on appropriate subsets of rings (e.g., Lie ideals, ideals, one sided ideals, etc.). These discussions and investigations can be found in works such as [
5,
6]. Moreover, the study of ∗-prime rings has further extended several well established results concerning prime rings, as demonstrated in [
7,
8]. These works also provide additional references on the subject. For more results related to derivations, one may refer to sources such as [
9,
10,
11,
12].
In [
13], Ashraf and Rehman established a significant result pertaining to prime rings. According to this result, if a prime ring
R possesses a derivation, denoted as ‘
’, which fulfills either of the following conditions:
for every
where
J represents a non-zero two-sided ideal of
then it necessarily follows that
R must be a commutative ring. In [
14] Ali et al. demonstrated that if a prime ring
R of char(
R)
with involution of the second-kind allows the existence of a non-zero derivation
satisfying
or
for all
a in
then
R must be a commutative ring. The aforementioned results can be viewed as specific cases derived from our more general result stated in Theorem 4 (i) and (ii), where the order of
is restricted to two and
is equal to
. Several related generalizations of these results exist in the literature (e.g., [
15]).
In the case of a nonempty subset
B of a ring
a map
is referred to as a centralizing (resp. commuting) map on
B if
(resp.
) holds for every
The investigation of centralizing and commuting maps traces its roots back to 1955, when Divinsky [
16] demonstrated that a simple Artinian ring becomes commutative if it possesses a commuting automorphism that is distinct from the identity mapping. Shortly thereafter, in 1957, Posner [
17] established that a prime ring must also be commutative if it accommodates a nonzero centralizing derivation. In 1970, Luh [
18] extended Divinsky’s findings to prime rings. Subsequently, Mayne [
19] derived a corresponding result to Posner’s for centralizing automorphisms that are not the identity. The culmination of these investigations is reflected in the comprehensive works of [
20,
21,
22,
23]. This research article aims to examine the aforementioned results within the context of prime rings that possess antiautomorphisms.
Consider a ring
R with involution ∗ and a nonempty subset
B of
A map
from
R to itself is termed ∗-centralizing on
B if the expression
belongs to the center of
R for every
and
In particular, when
equals zero for every
and
the map
is referred to as ∗-commuting on
In case
it said to be skew ∗-centralizing and skew ∗-commuting on
respectively. In 2022, Rehman and Alnoghashi [
24] generalized the previous concepts to (skew)
-centralizing and (skew)
-commuting, where
is an antiautomorphism and
is a generalized derivation on
that is,
belongs to the center of
R or equals zero, for every
respectively. In [
25,
26], Ali and Dar, embarked on the investigation of these maps and demonstrated that the presence of a nonzero ∗-centralizing derivation in a prime ring of char(
R)
with a second-kind involution leads to the ring being commutative. They also demonstrated the ∗-version of Posner’s second theorem and its associated issues in addition to characterising these maps in semiprime and prime rings with involution. For more details about Posner’s second theorem see [
17]. In 2017, Nejjar et al. [
27] (Theorem 3.7) also achieved congruent outcomes, further corroborating the aforementioned results.
If
whenever
for every
a and
b in
then a mapping
preserves commutativity. The preservation of commutativity has been an active area of research in matrix theory, operator theory, and ring theory (refer to [
28] for further details). Let
B be a subset of
a mapping
is referred to as strong commutativity-preserving (SCP) if
holds for every
a and
b in
Bell and Daif examined the possibility of rings admitting a derivation that is SCP on a nonzero right ideal in [
29]. They demonstrated that if a semiprime ring
R possesses a derivation
satisfying
for any
a and
b in a right ideal
L of
then
Furthermore, if
then
R is commutative. Deng and Ashraf later presented a result in [
30], stating that a semiprime ring
R has a nonzero central ideal if it has a derivation
and a mapping
defined on a nonzero ideal
such that
for any
a and
b in
In particular, they established that if
then
R is commutative. If a mapping
satisfies
for every
a and
b in a subset
S of
it is termed skew strong commutativity-preserving (skew SCP). Ali and Huang proposed that a nonzero central ideal is contained in
R when
R is a 2-torsion-free semiprime ring and
is a derivation of
R that satisfies the skew SCP on a nonzero ideal
L of
R [
31]. There exist numerous related generalizations of these results within the literature (see for example, [
32]).
Inspired by the concept of ∗-SCP derivation, in 2017, Nejjar et al. [
27] embarked on investigating a broader and more comprehensive notion by exploring the identity
for every element
Their objective was to examine the implications of this identity within the context of a prime ring
R of char(
R)
with an involution ∗ of the second-kind. In their work [
27] (Theorems 3.1, 3.5 and 3.8) they successfully established that if
R admits a non-zero derivation, denoted as
that satisfies the condition
for every element
and
then the ring must necessarily be commutative. The previous results are a special case of our result when the order of
is equal to two and
in Theorem 2.
In their notable work, Mamouni et al. [
33] (2021) made a significant contribution to the study of prime rings. They established a compelling result that holds true for prime rings denoted as
R. According to their results, if such a prime ring of char(
R)
with an involution ∗ of the second-kind possesses two derivations, denoted as
, that satisfies any of the following conditions:
([
33] (Theorem 1)),
([
33] (Theorem 2)),
([
33] (Theorem 3)) for every
, where
then it can be concluded that the ring
R must be a commutative ring. The previous results are a special case of our result when the order of
is equal to two in Theorems 1 and 2.
Based on the motivations above and observations, the goals and objectives of this article are to establish the following main results:
Theorem 1. Let R be a prime ring of char(R) equipped with an antiautomorphism Λ which is Z-nonlinear and let be nonzero derivations on Then for every and the following conditions are equivalent.
- (i)
- (ii)
- (iii)
R is commutative.
Theorem 2. Let R be a prime ring of char(R) , equipped with an antiautomorphism Λ which is Z-nonlinear and let be derivations on Then for every and the following conditions are equivalent.
- (i)
- (ii)
R is commutative.
Theorem 3. Let R be a prime ring of char(R) , equipped with an antiautomorphism Λ which is Z-nonlinear and let be derivations on Then for every and the following conditions are equivalent.
- (i)
- (ii)
- (iii)
R is commutative.
Theorem 4. Let R be a prime ring of char(R) , equipped with an antiautomorphism Λ which is Z-nonlinear and let be derivations on Then for every and the following conditions are equivalent.
- (i)
- (ii)
- (iii)
- (iv)
R is commutative.
3. The Main Results
To prove our results, we require a set of auxiliary lemmas. Let us commence with the following:
Lemma 1. If for every and then R is commutative.
Proof. Assume that
for every
and
By linearizing (
1), we obtain
for every
and
Let
Replacing
b by
in (
2), we have
Again, replacing
a by
in (
3), we obtain
That is,
Multiplying (
2) by
z and then using it in the previous expression, we see that
Taking
a by
in the last relation and using it, we find that
Since there is
such that
we arrive at
Putting
a by
in the last expression, we conclude that
Replacing
b by
z in (
4), we infer that
That is,
for every
or
In case
for every
we have
R is commutative. If
then
Using (
5) in (
4), we obtain
Hence,
or
Suppose that
for every
and by Fact 4, we find that
R is commutative. If
then
by (
5). Using fact that
in (
3), see that
Multiplying (
2) by
z and then using it in the previous expression, we find that
Hence,
That is,
Putting
in (
6), we infer that
and so
is a derivation of
where
and hence
and by Fact 5, we conclude that
R is commutative or
In case
we have
By using (
7) in (
6), we obtain
In particular,
and by Fact 5, we have
or
R is commutative. In case
and from (
7), we see that
□
Lemma 2. If for every and then R is commutative.
Proof. Assume that
for every
and
By linearizing (
8), we have
for every
and
Let
Replacing
b by
in (
9), we obtain
Again, replacing
a by
in (
10), we obtain
Multiplying (
9) by
and then using it in the previous expression, we see that
Taking
a by
in (
11) and then multiplying it by
z and then subtracting them, we obtain
Hence,
Putting
in the last relation, we conclude that
That is,
for every
or
If
for every
then
R is commutative. If
then
Multiplying (
9) by
z and then using it in (
10), we have
Replacing
a by
in the last relation and then multiplying it by
z and then subtracting them, we obtain
That is,
Hence,
or
If
then
and by Fact 6, we conclude that
R is commutative. Now, in case
using the last relation in (
13), we see that
By using (
15) in (
14), we find that
That is,
Putting
in (
16) and using (
15), we conclude that
That is,
and by Fact 5, we infer that
or
R is commutative. In case
using the last relation in (
16), we have
and so
or
R is commutative. □
Based on Lemmas 1 and 2, the proof of Theorem 1 follows.
Lemma 3. If for every and then R is commutative.
Proof. Assume that
for every
and
Taking
a by
in (
17), where
we obtain
and so
Hence,
If
or
is an outer derivation, then from (
17) and by Fact 7, we obtain
(in case
is an outer derivation) for every
Putting
in the last relation, we obtain
and by Fact 4,
R is commutative. Now, if
and
are inner derivations, then from (
18), we obtain
for every
and some
Putting
in the previous expression, we see that
Again, putting
a by
in the last expression and using it, where
we find that
and so
or
If
for every
then
R is commutative. If
for every
then
and so
Using the previous expression in (
17), we infer that
and by Fact 4, we find that
R is commutative. □
Lemma 4. If for every and then R is commutative.
Proof. Assume that
for every
and
By linearizing (
19), we obtain
for every
Let
Replacing
b by
in (
20), we obtain
Putting
in (
21) and using (
19), we find that
Linearizing (
22), we arrive at
for every
Taking
a by
in (
23), we conclude that
Multiplying (
23) by
z and the using it in (
24), we have
Replacing
b by
in (
25), we find that
Multiplying (
25) by
z and the using it in the last relation, we obtain
That is,
Hence,
or
In case Putting in the previous expression, we see that and by Fact 6, R is commutative. Suppose that
Case (I):
Multiplying (
20) by
z and subtracting it from (
21) and using (
26), we infer that
That is,
Hence,
Using Lemma 3 in the previous expression, we find that
R is commutative.
Case (II):
Using (
27) in (
23), we conclude that
Thus,
Taking
b by
in the previous expression and using (
27) and then multiplying it by
z and then subtracting them, we have
Hence,
That is,
Putting
in (
28), we obtain
If
then
and so
and by Fact 5, we obtain
or
R is commutative. In case
using the last relation in (
19), we see that
and by Fact 6,
R is commutative. In case
we infer that
In particular,
and by Fact 5, we conclude that
or
R is commutative. In case
use similar arguments as the above.
Case (III): Now, applying similar arguments as used in Case (II), we obtain and then using the same technique as above, we find that R is commutative. □
By utilizing Lemma 4, we obtain the proof for Theorem 2.
Lemma 5. If for every and then R is commutative.
Proof. Assume that
for every
and
By linearizing (
29), we have
for every
and
Let
Replacing
b by
in (
30), we obtain
Putting
in (
31), we obtain
Multiplying (
30) by
z and then using it in the last relation, we obtain
By linearizing (
32), we find that
Taking
b by
in the last relation and using (
32), we infer that
That is,
or
In case
and by Fact 6,
R is commutative. If
then
or
Case (I): Suppose that
Using (
33) in (
31), we have
Multiplying (
30) by
z and then using it in the last relation, we get
This implies that
and so
Suppose that
or
is an outer derivation, and by Fact 7, we obtain
and hence
R is commutative. Now, we assume that
and
are inner derivations, thus (
34) becomes
for some
Putting
in the previous expression, we see that
that is
for every
Therefore,
R is commutative.
Case (II): Suppose that
Using the last relation in (
31), we obtain
Multiplying (
30) by
z and using it in the last relation, we obtain
Putting
in the previous expression and using (
35), we see that
Now, in case
we have
and hence
R is commutative. Suppose that
Then
Replacing
a by
in the previous expression and using (
35), we find that
Multiplying (
36) by
and using the last relation, we conclude that
This implies that
Thus,
R is commutative.
Case (III): Suppose that Use similar arguments as in Case (II). □
Lemma 6. If for every and then R is commutative.
Proof. Using the same arguments as we have used in the proof of Lemma 5, we obtain the required result. □
Lemma 7. If for every and then R is commutative.
Proof. Assume that
for every
By linearizing (
37), we have
for every
Replacing
a by
in (
38), where
we obtain
for every
Multiplying (
38) by
z and using (
39), we obtain
for every
Taking
a by
in (
39), we see that
for every
Multiplying (
40) by
and using (
41), we find that
Hence,
for every
Replacing
a by
in (
42) and using it, we have
and so
that is
or
Case (I): Suppose that
Using the last relation in (
42), we obtain
implies that
that is
and so
or
Subcase 1: Suppose that
This means
and by Fact 5, we obtain
R is commutative or
In case
Using the last relation in (
37), we see that
it follows that
and by Fact 6, we find that
R is commutative.
Subcase 2: Suppose that
From (
40), we have
and so
Putting
in the previous expression, we obtain
that is
Hence,
R is commutative.
Case (II): Suppose that Using the same arguments as used in Subcase 1. □
Lemma 8. If for every and then R is commutative.
Proof. Using the same arguments as we have used in the proof of Lemma 7, we obtain the required result. □
Lemma 9. If for every and then R is commutative.
Proof. Assume that
Linearizing (
43), we have
Replacing
a by
in (
44), we obtain
Multiplying (
44) by
z and then using (
45), we obtain
Taking
a by
in (
46), we see that
Multiplying (
46) by
and then using (
47), we find that
Hence,
Now, application of similar arguments as used in (
42), we obtain
R is commutative, except Subcase 2, we obtain
and by using the previous expression in (
46), we obtain
That is,
If
or
is outer, then we can put
or
by any element in
R, by Fact 7, let any one of them be zero, and so we obtain
This implies that
and by Fact 4,
R is commutative. Now, if
and
are inner, then
for some
Taking
in (
48), we find that
Putting
we conclude that
and so
for every
Hence,
R is commutative. Suppose that
We have
Replacing
a by
in (
49), we obtain
Using (
49) in the previous expression, we find that
That is
Taking
a by
in the previous expression and using it, we obtain
This implies that
Thus,
or
In both cases it implies that
and so (
49) reduce to
and so
and by Fact 4, we find that
R is commutative. □
Example 2. - (i)
The example demonstrates the significance of the condition “Λ is Z-nonlinear" in Theorems 2–4: Consider and Λ correspond to any element in the prime ring of real quaternions such that it maps to its conjugate.
- (ii)
To illustrate the importance of the hypothesis “the primeness of R" is essential in our results: Let and for every where Then Λ is a Z-nonlinear antiautomorphism, and Ξ is derivation on and R is not commutative.
Remark 1. In the case where Λ represents an automorphism, all the results presented in this article remain valid.
It is important to emphasize that our results in this article hold valid even when the different assumptions are presumed to be true on a non-zero ideal rather than the entire ring