scholarly journals On transposes of nilpotent matrices over arbitrary rings

1977 ◽  
Vol 23 (3) ◽  
pp. 366-370 ◽  
Author(s):  
Thomas P. Kezlan
Keyword(s):  
Division Ring ◽  
Polynomial Identity ◽  
Jacobson Radical ◽  
Commutator Ideal ◽  
Nilpotent Elements ◽  
Nilpotent Matrices

AbstractIt is shown that if every nilpotent 2 × 2 matrix over a ring has nilpotent transpose, then the commutator ideal must be contained in the Jacobson radical, thus generalizing a result of R. S. Gupta, who considered the division ring case. Moreover, if the nilpotent elements form an ideal or if the ring satisfies a polynomial identity, then the above property of the transpose implies that in fact the commutator ideal must be nil.

scholarly journals On commutativity in certain rings

1970 ◽  
Vol 2 (1) ◽  
pp. 107-115 ◽  
Author(s):  
H.G. Moore
Keyword(s):  
Positive Integer ◽  
Polynomial Identity ◽  
Associative Ring ◽  
Arbitrary Element ◽  
Alternative Ring ◽  
Commutator Ideal ◽  
Integer Coefficients ◽  
Nilpotent Elements ◽  
Fixed Positive Integer ◽  
Associative Rings

I.N. Herstein has shown that an associative ring in which the nilpotent elements are “well-behaved”, and such that every element satisfies a certain polynomial identity, is commutative. This result is generalized here. Specifically, it is shown that an alternative ring R which satisfies the following three properties is commutative:(i) for x ∈ R, there exists an integer n(x) and a polynomial px (t) with integer coefficients such that xn+1p(x) = xn;(ii) for a fixed positive integer m, a a nilpotent and b an arbitrary element of R, a - am commutes with b - bm;(iii) for the same m, a and b, (ab+b)m = (ba+b)m and (ab)m = ambm.Examples are given to show that all three properties are essential, and it is shown that for associative rings certain modified versions of these properties are individually enough to assure that the commutator ideal of the ring is nil.

scholarly journals A note on extensions of Baer and P. P. -rings

1974 ◽  
Vol 18 (4) ◽  
pp. 470-473 ◽  
Author(s):  
Efraim P. Armendariz
Keyword(s):  
Left Ideal ◽  
Polynomial Identity ◽  
Polynomial Rings ◽  
Nilpotent Elements ◽  
Baer Ring ◽  
Baer Rings ◽  
Left Annihilator

Baer rings are rings in which the left (right) annihilator of each subset is generated by an idempotent [6]. Closely related to Baer rings are left P.P.-rings; these are rings in which each principal left ideal is projective, or equivalently, rings in which the left annihilator of each element is generated by an idempotent. Both Baer and P.P.-rings have been extensively studied (e.g. [2], [1], [3], [7]) and it is known that both of these properties are not stable relative to the formation of polynomial rings [5]. However we will show that if a ring R has no nonzero nilpotent elements then R[X] is a Baer or P.P.-ring if and only if R is a Baer or P.P.-ring. This generalizes a result of S. Jøndrup [5] who proved stability for commutative P.P.-rings via localizations – a technique which is, of course, not available to us. We also consider the converse to the well-known result that the center of a Baer ring is a Baer ring [6] and show that if R has no nonzero nilpotent elements, satisfies a polynomial identity and has a Baer ring as center, then R must be a Baer ring. We include examples to illustrate that all the hypotheses are needed.

Unitaries in Simple Artinian Rings

1979 ◽  
Vol 31 (3) ◽  
pp. 542-557
Author(s):  
M. Chacron
Keyword(s):  
Division Ring ◽  
Polynomial Identity ◽  
Artinian Ring ◽  
Artinian Rings ◽  
Conjugate Transpose ◽  
Torsion Free

Let R be a 2-torsion free simple artinian ring with involution*. The element u of R is said to be unitary if u is invertible with inverse u*. In this paper we shall be concerned with the subalgebras W of R over its centre Z such that uWu* ⊆ W, for all unitaries u of R. We prove that if R has rank superior to 1 over a division ring D containing more than 5 elements and if R is not 4-dimensional then any such subalgebra W must be one of the trivial subalgebras 0, Z or R, under one of the following extra finiteness assumptions: W contains inverses, W satisfies a polynomial identity, the ground division ring D is algebraic, the involution is a conjugate-transpose involution such that D equipped with the induced involution is generated by unitaries.

scholarly journals Rings with a finite set of nonnilpotents

1979 ◽  
Vol 2 (1) ◽  
pp. 121-126 ◽  
Author(s):  
Mohan S. Putcha ◽  
Adil Yaqub
Keyword(s):  
Division Ring ◽  
Nonnegative Integer ◽  
Finite Ring ◽  
Structure Theory ◽  
Nilpotent Elements ◽  
Finite Set ◽  
Semisimple Ring ◽  
Nil Ring ◽  
Primitive Ring

LetRbe a ring and letNdenote the set of nilpotent elements ofR. Letnbe a nonnegative integer. The ringRis called aθn-ring if the number of elements inRwhich are not inNis at mostn. The following theorem is proved: IfRis aθn-ring, thenRis nil orRis finite. Conversely, ifRis a nil ring or a finite ring, thenRis aθn-ring for somen. The proof of this theorem uses the structure theory of rings, beginning with the division ring case, followed by the primitive ring case, and then the semisimple ring case. Finally, the general case is considered.

Local Group Rings

1972 ◽  
Vol 15 (1) ◽  
pp. 137-138 ◽  
Author(s):  
W. K. Nicholson
Keyword(s):  
Division Ring ◽  
Jacobson Radical ◽  
Local Group ◽  
Group Rings

The purpose of this note is to generalize a result of Gulliksen, Ribenboim and Viswanathan which characterized local group rings when both the ring and the group are commutative.We assume throughout that all rings are associative with identity. If R is a ring we call R local if R/J(R) is a division ring where J(R) denotes the Jacobson radical of R. It is well known that R is local if and only if each element of R\J(R) is a unit. We need the following.

scholarly journals On Generalized Periodic-Like Rings

2007 ◽  
Vol 2007 ◽  
pp. 1-5 ◽  
Author(s):  
Howard E. Bell ◽  
Adil Yaqub
Keyword(s):  
Jacobson Radical ◽  
Opposite Parity ◽  
Basic Properties ◽  
Nilpotent Elements ◽  
Positive Integers

LetRbe a ring with centerZ, Jacobson radicalJ, and setNof all nilpotent elements. CallRgeneralized periodic-like if for allx∈R∖(N∪J∪Z)there exist positive integersm,nof opposite parity for whichxm−xn∈N∩Z. We identify some basic properties of such rings and prove some results on commutativity.

Density of Polynomial Maps

2010 ◽  
Vol 53 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Chen-Lian Chuang ◽  
Tsiu-Kwen Lee
Keyword(s):  
Positive Integer ◽  
Finite Field ◽  
Vector Space ◽  
Prime Ring ◽  
Division Ring ◽  
Polynomial Identity ◽  
Matrix Ring ◽  
Polynomial Maps ◽  
Finite Matrix ◽  
Nonzero Polynomial

AbstractLet R be a dense subring of End(DV), where V is a left vector space over a division ring D. If dimDV = ∞, then the range of any nonzero polynomial ƒ (X1, … , Xm) on R is dense in End(DV). As an application, let R be a prime ring without nonzero nil one-sided ideals and 0 ≠ a ∈ R. If a f (x1, … , xm)n(xi) = 0 for all x1, … , xm ∈ R, where n(xi ) is a positive integer depending on x1, … , xm, then ƒ (X1, … , Xm) is a polynomial identity of R unless R is a finite matrix ring over a finite field.

scholarly journals A generalization of a theorem of Wedderburn

1973 ◽  
Vol 8 (2) ◽  
pp. 181-185 ◽  
Author(s):  
Steve Ligh
Keyword(s):  
Division Ring ◽  
Commutative Rings ◽  
Left Identity ◽  
Nilpotent Elements

Outcalt and Yaqub have extended the Wedderburn Theorem which states that a finite division ring is a field to the case where R is a ring with identity in which every element is either nilpotent or a unit. In this paper we generalize their result to the case where R has a left identity and the set of nilpotent elements is an ideal. We also construct a class of non-commutative rings showing that our generalization of Outcalt and Yaqub's result is real.

scholarly journals On some infinitely presented associative algebras

1973 ◽  
Vol 16 (3) ◽  
pp. 290-293 ◽  
Author(s):  
Jacques Lewin
Keyword(s):  
Associative Algebra ◽  
Commutative Algebra ◽  
Polynomial Identity ◽  
Finite Dimension ◽  
Negative Answer ◽  
Free Associative Algebra ◽  
Finitely Generated ◽  
Associative Algebras ◽  
Commutator Ideal ◽  
Finitely Presented

We prove here that if F is a finitely generated free associative algebra over the field and R is an ideal of F, then F/R2 is finitely presented if and only if F/R has finite dimension. Amitsur, [1, p. 136] asked whether a finitely generated algebra which is embeddable in matrices over a commutative f algebra is necessarily finitely presented. Let R = F′, the commutator ideal of F, then [4, theorem 6], F/F′2 is embeddable and thus provides a negative answer to his question. Another such example can be found in Small [6]. We also show that there are uncountably many two generator I algebras which satisfy a polynomial identity yet are not embeddable in any algebra of n xn matrices over a commutative algebra.

A Trace Condition Equivalent to Simultaneous Triangularizability

1986 ◽  
Vol 38 (2) ◽  
pp. 376-386 ◽  
Author(s):  
Heydar Radjavi
Keyword(s):  
Division Ring ◽  
Sufficient Conditions ◽  
Invertible Matrix ◽  
Multiplicative Semigroup ◽  
Nilpotent Matrices

A collection of matrices over a field F is said to be triangularizable if there is an invertible matrix T over F such that the matrices T−1ST, are all upper triangular. It is a well-known and easy fact that any commutative set is triangularizable if F is algebraically closed, or if F contains the spectrum of every member of . Many sufficient conditions are known for triangularizability of matrix collections. Levitzki [7] proved that a (multiplicative) semigroup of nilpotent matrices is triangularizable. (His result is valid even over a division ring.) Kolchin [5] showed the triangularizability of a semigroup of unipotent matrices, i.e., matrices of the form I + N with N nilpotent. Kaplansky [3, 4] unified and generalized these results.

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