3. The Main Results
Park in [
14] proved various interesting results for symmetric
n- derivations like generalization to the famous Posner’s result (cf.; [
15]) and several other results. Some of his initial work on
n-derivations which paved way for future developments in this area are also provided in the same paper. In 2014, Ashraf and Jamal [
5] introduced certain interesting identities that help us reveal the structure of any ring, similar to the work of Daif and Bell on semiprime rings [
9]. They demonstrated that a ring
T is commutative if there exists a symmetric
n-additive map
satisfying certain functional identities. Also, in case of
n-derivations Ashraf et al. in [
4] developed upon the line of inquiry provided by Park in the case of prime rings. Ashraf et al. [
6] used properties of an ideal and the trace of symmetric
n-derivations to achieve results for the existence of central ideals which eventually helps to see the commutativity of the rings under consideration. Recently, Ali et al. in [
2] presented several findings regarding the containment of a nonzero central ideal in a ring
T that adheres to specific functional identities involving the traces
d and
g of symmetric
n-derivations
D and
G, respectively. In addition to proving results about the traces of permuting
n-derivations, they studied the relation between
n-derivations and
n-multipliers and provided a characterization of symmetric
n-derivations of prime rings in terms of left
n-multipliers. A similar study of characterization of symmetric reverse
n-derivations in terms of
n-multipliers seems an interesting concept to venture out. Motivated by the existing work on symmetric
n-derivations, we wish to explore rings specifically semiprime rings so that to understand the behavior of symmetric reverse
n-derivations.
In this paper, we examine two main aspects of symmetric reverse n-derivations. First, we investigate their behavior when the trace is zero on an ideal. Second, we explore some identities involving trace itself. Previous research has demonstrated the crucial role played by the trace function in the study of n-derivations. Therefore, our focus is directed towards understanding the trace and some associated maps. One of the primary contributions of this paper lies in analyzing how the trace influences the structure of symmetric reverse n-derivations. Additionally, we highlight new properties of trace maps when restricted to ideals. This provides a deeper insight into how reverse n-derivations behave under specific constraints. The results obtained extend few existing findings on symmetric n-derivations to that of symmetric reverse n-derivations. The first important result of this paper is the following:
Theorem 1. Let be a fixed integer, T be a -torsion free semiprime ring and J its non-zero ideal. If there exists a symmetric reverse n-derivation on T with trace f such that , then .
Proof. By the hypothesis, we have
Substituting
by
, where
for
, we obtain
which is given by
Using the given hypothesis, we get
Lemma 1 allows us to equate coefficients to 0, we can write
and using torsion restrictions, we have
Substitute
again by
(where
and
), we get
Computing further, we obtain
This process can be continued until we obtain
So, from
we arrive at
. Now, replace
by
in (
1), to obtain
Using equation (
1), we arrive at
Now, replace
by
with
, we get
Continuing in the same manner, we finally obtain
In the above equation replace
by the term
we get
for all
. Since
T is semiprime, so by invoking Lemma 3, we obtain
for all
. Continuing in the similar manner, we can keep on omitting
’s one by one and obtain
Lastly, replace
by
to arrive at,
Therefore, using Lemma 3, we get
which is the required conclusion. Hence,
. □
Theorem 2. Let T be -torsion free semiprime ring, J be a non-zero ideal of T and a symmetric reverse n-derivation on T with trace f. If any one of the following conditions holds in T, then f is commuting on J:
for all ,
, for all ,
, for all
Proof. 1. By hypothesis, we have
Taking
ℓ in place of
,
,
, we get
Using the hypothesis, we get
Application of Lemma 1 yields
Since
T is
-torsion free, we obtain
Hence, Proposition 2 implies f is commuting on J.
Replace
ℓ by
,
, we get the following calculations
and
Application of the hypothesis yields
Using Lemma 1 and torsion restrictions, we have
Substituting
by
ℓ, we get
So, the given hypothesis boils down to,
By Proposition 2, we conclude that f is commuting on J.
Replacement of
ℓ by
,
,
, yields
Using the given condition, we get
By applying Lemma 1 and the torsion restrictions, we obtain
Again replace
by
ℓ, we then have
From the hypothesis, we arrive at
In view of Proposition 2, we obtain to our desired conclusion. □
Theorem 3. Let T be -torsion free semiprime ring, J be a non-zero ideal of T and a symmetric reverse n-derivation on T with trace f. If any one of the following conditions holds in T, then f is commuting on J:
, for all ,
, for all ,
, for all
Proof.
Now, substitute
ℓ by
,
,
, we get
Application of hypothesis gives,
On solving further, we get
and
Replacing
by
ℓ in the above expression, we get
Using the hypothesis, we obtain
Therefore, Proposition 1 implies f is commuting on J.
Substitute
ℓ by
, so that
Using the given hypothesis, we get
Application of Lemma 1 and torsion restrictions yields
By the hypothesis, we conclude
Hence, f is commuting on J.
Replace
ℓ by
,
,
, we get
Using the hypothesis, we get
By using Lemma 1 and the torsion restrictions, we obtain
Replacing
by
ℓ in the above expression, we have
In view of Proposition 1, we get the desired conclusion. □
Theorem 4. Let T be -torsion free semiprime ring, J be a non-zero ideal of T and a symmetric reverse n-derivation on T with trace f. If for all . Then, f is commuting on J.
Proof.
Replace
ℓ by
,
,
, we see that
On solving it further, we get
and
From the given hypothesis the above expression reduces to,
Application of Lemma 1 yields
Replacing
by
ℓ provides,
Therefore, we have
and hence from Proposition 2, we conclude that
f is commuting on
J. This completes the proof. □
Theorem 5. Let T be -torsion free semiprime ring, J be a non-zero ideal of T and a symmetric reverse n-derivation on T with trace f. If any one of the following conditions hold
, for all ,
, for all ,
, for all
then T contains a non-zero central ideal.
Proof.
On replacing
ℓ by
,
,
we get
Using the given hypothesis, we obtain
for all
. The application of Lemma 1 yields,
Since
T is
-torsion free, so we get
Replace
by
ℓ in the above equation to obtain
Using this in the given hypothesis we get
On commuting it with any
, we obtain
Replacing
ℓ by
where
, we see that
Now substitute
in place of
to get
So we can write
that gives
Taking ℓ to be and using the semiprimeness of T, we get . Hence, J is a non-zero central ideal in T.
2. Using similar arguments as done in part 1, we obtain the desired conclusion.
Substitute
in place of
ℓ,
,
to obtain
Using the given hypothesis, we arrive at
for all
. In view of Lemma 1, we have
Since
T is
-torsion free, so we have
On replacing
by
ℓ in the above equation, we obtain
Thus, from the hypothesis we can conclude
Application of Lemma 4 gives us the existence of a non-zero central ideal in T. Hence, the desired result. □
The subsequent example illustrates that the requirement of semiprimeness for T in Theorems 5 is indispensable and cannot be overlooked. The following example justifies this fact:
Example 33. Consider the ring . Next let be an ideal of T. Denote where , , and let us define by with trace define by . One can easily check that is a symmetric reverse n-derivation such that all the conditions in Theorems 5 are satisfied. However, J is non-central ideal. Hence, in Theorem 5, the hypothesis of semiprimeness can not be omitted.