scholarly journals Commutativity theorems for rings with polynomial constraints on certain subsets

1991 ◽  
Vol 43 (3) ◽  
pp. 451-462 ◽  
Author(s):  
Hiroaki Komatsu ◽  
Hisao Tominaga

We prove several commutativity theorems for unital rings with polynomial constraints on certain subsets, which improve and generalise the recent results of Grosen, and Ashraf and Quadri.

1990 ◽  
Vol 13 (4) ◽  
pp. 769-774
Author(s):  
Hamza A. S. Abujabal

In this paper we generalize some well-known commutativity theorems for associative rings as follows: LetRbe a lefts-unital ring. If there exist nonnegative integersm>1,k≥0, andn≥0such that for anyx,yinR,[xky−xnym,x]=0, thenRis commutative.


1992 ◽  
Vol 23 (3) ◽  
pp. 253-268
Author(s):  
H. A. S. ABUJABAL ◽  
M. A. KHAN ◽  
M. S. SAMMAN

In the present paper, we study the commutativity of one sided s-unital rings satisfying conditions of the form $[x^r y\pm x^ny^mx^s,x]= 0 = [x^ry^m\pm x^ny^{m^2}x^s, x]$, or $[yx^r\pm x^ny^mx^s, x] = 0 = [y^mx^r\pm x^ny^{m^2}x^s, x]$ for each $x$,$y \in R$, where $m = m(y) > 1$ is an integer depending on $y$ and $n$, $r$ and $s$ are fixed non-negative integers. Other commutativity theorems are also obtained. Our results generalize·some of the well-known commutativity theorems for rings.


1992 ◽  
Vol 21 (3-4) ◽  
pp. 256-263
Author(s):  
Hamza A. S. Abujabal ◽  
Veselin Peric

1997 ◽  
Vol 20 (2) ◽  
pp. 267-270
Author(s):  
Murtaza A. Quadri ◽  
V. W. Jacob ◽  
M. Ashraf

The main theorem proved in the present paper states as follows “Letm,k,nandsbe fixed non-negative integers such thatkandnare not simultaneously equal to1andRbe a left (resp right)s-unital ring satisfying[(xmyk)n−xsy,x]=0(resp[(xmyk)n−yxs,x]=0) ThenRis commutative.” Further commutativity of lefts-unital rings satisfying the conditionxt[xm,y]−yr[x,f(y)]xs=0wheref(t)∈t2Z[t]andm>0,t,randsare fixed non-negative integers, has been investigated Finally, we extend these results to the case when integral exponents in the underlying conditions are no longer fixed, rather they depend on the pair of ring elementsxandyfor their values. These results generalize a number of commutativity theorems established recently.


1993 ◽  
Vol 24 (1) ◽  
pp. 23-28
Author(s):  
M. ASHRAF ◽  
M. A. QUADRI ◽  
V. W. JACOB

In the present paper we discuss the commutativity of certain rings, namely rings with unity 1 and right s-unital rings under each of the following conditions: \[ (P1)[yx^m - x^nf (y), x] = 0, \quad (P1)^*[yx^m - f (y)x^n, x] = 0, \] where $m$, $n$ are fixed non-negative integers and $f(x)$ is a polynomial in $X^2\mathbb{Z}(X)$ varying with the pair of ring elements $x$, $y$. Further, the results have been extended to the case when $m$ and $n$ depend on the choice of $x$ and $y$ and the ring satisfies the Chacron's condition.


1989 ◽  
Vol 15 (3-4) ◽  
pp. 335-342 ◽  
Author(s):  
Hiroaki Komatsu ◽  
Hisao Tominaga

1991 ◽  
Vol 22 (3) ◽  
pp. 285-297
Author(s):  
MOHD ASHRAF

We first prove that a ring $R$ with unity 1 is corrunutalive if and only if for each $x$ in $R$ either $x$ is central or there exists a polynomial $f(t) \in Z[t]$ such that $x- x^2f(x) \in A$, where $A$ is a nil subset of $R$ (not necessarily a subring of $R$) and $R$ stisfies any one of the conditions $[x, x^my- x^py^nx^q] =0$ and $[x,yx^m-x^Py^nx^q]=0$ for all $x,y$ in $R$, where $m\ge 0$, $n >1$, $p \ge 0$, $q \ge 0$ are integers depending on pair of elements $x$, $y$. Further the same result has been extended for one sided $s$-unital rings. Finally a related result for a nil commutative subset $A$ is also obtained.


1998 ◽  
Vol 5 (4) ◽  
pp. 301-314
Author(s):  
H. A. S. Abujabal ◽  
M. A. Khan

Abstract We first establish the commutativity for the semiprime ring satisfying [xn, y]xr = ±ys [x, ym ]yt for all x, y in R, where m, n, r, s and t are fixed non-negative integers, and further, we investigate the commutativity of rings with unity under some additional hypotheses. Moreover, it is also shown that the above result is true for s-unital rings. Also, we provide some counterexamples which show that the hypotheses of our theorems are not altogether superfluous. The results of this paper generalize some of the well-known commutativity theorems for rings which are right s-unital.


1990 ◽  
Vol 13 (2) ◽  
pp. 315-319
Author(s):  
H. A. S. Abujabal ◽  
M. S. Khan

Through much shorter proofs, some new commutativity theorems for rings with unity have been obtained. These results either extend or generalize a few well-known theorems. Our method of proof is based on an iteration technique.


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