A Remark on the Classifications of Rhotrices As Abstract Structures

Full Length Research Paper

A remark on the classifications of rhotrices as abstract structures

A. Mohammed

Department of Mathematics, Ahmadu Bello University, Zaria, Nigeria. E-mail: [email protected]. Tel: +2348065519683.

Accepted 10 July, 2009

This paper presents additional classifications of rhotrices as abstract structures of Ring, Field, Integral Domain, Principal Ideal Domain and Unique Factorization Domain, as a sort of an additional work to our earlier classifications of rhotrices as algebraic structures of Groups, Semi groups, Monoids and Boolean Algebra. Rhotrix is a new paradigm of matrix theory, concerned with representing arrays of real numbers in mathematical rhomboid form, as an extension of ideas on matrix-tertions and matrix noitrets proposed by Atanassov and Shannon.

Key words: Rhotrices, ring, field, integral domain, principal ideal domain, unique factorization domain.

INTRODUCTION

The interest to stimulate ideas on how to imagine new that all rhotrices are of odd dimension. For example, a forms of mathematical rhomboid arrays and their classify- rhotrix S of dimension 7 is given by cations as abstract structures of Groups, Semi-groups, Monoids, and Boolean Algebra was first proposed by a Mohammed (2007a) as part of a note on enrichment b c d exercises through extension to rhotrices. Thus, the pur- e f g h i pose of this paper is to outlines development of abstract S = j k l h(S ) n o p structures of Ring, Field, Integral Domain (ID), Principal q r s t u Ideal Domain (PID) and Unique Factorization Domain v w x (UFD) of rhotrices, as a remark to the earlier work y discussed in Mohammed (2007a) The initial concept and analysis of rhotrix was intro- The binary operations of addition (+), scalar multipli- duced by Ajibade (2003), as objects which are, in some cation, and multiplication (o) defined in (Ajibade, 2003) ways, between (2x2) –dimensional and (3x3)-dimensional (respectively, recorded below) that were adopted in matrices, defined by Mohammed (2007a) will also be adopted in this paper for the development of the additional abstract structures: À a ¤ Œ Œ (1.1) R = Ã b c d : a, b, c, d , e ∈ ℜ ‹ À f ¤ Œ Œ Let Œ Œ be as Õ e › Q = Ã g h(Q) j : f , g, h(Q), j, k ∈ℜ‹ Œ Œ Õ k › Where; h(R) = c is called the heart of R. Extension in the size of R was considered possible but of interest defined (Ajibade, 2003) and then it follows that (Ajibade, 2003) is three dimensional rhotrix. It is worthy a f a+f noticing that an n-dimensional rhotrix R, denoted by Rn , R+Q= b h(R) d + g h(Q) j = b+g h(R)+h(Q) d+j , will have entries as card(Rn ) , where, e k e+k 1 2 card(Rn ) = 2 (n +1) , and n ∈ 2Ζ +1. This implies (1.2 Mohammed 497

a ∝ a (Mohammed, 2007b, 2008).

∝ R =∝ b h(R) d = ∝ b ∝ h(R) ∝ d It is noteworthy to mention that, the development of all the further abstract structures we present in this paper, e ∝ e are based on multiplication () defined (Ajibade, 2003). (1.3) Also, without any loss in generality, rhotrices of dimension three, considered to be the base rhotrices, will be and used to present our work, except where ever necessary. Thus, all the results stated in this paper are true for high ah (Q ) + fh(R) d i m e n s i o n a l r h o t r i c e s . RoQ = bh (Q) + gh (R) h(R)h(Q) dh (Q ) + jh(R) The following definitions may be noted as they will eh (Q ) + kh (R) serve on our discussions in section 3. (1.4) Definition 1: A rhotrix R is called a real rhotrix if all its In addition to these binary operations, the identity and entries belong to the set of Real Numbers. inverse of the rhotrix R were also defined, respectively, Definition 2: A rhotrix R is called an integer rhotrix if all by its entries belong to the set of Integer Numbers

0 The classifications of rhotrices as abstract structures I = 0 1 0 (1.5) In this section, we draw attention of our reader to the 0 paper (Mohammed, 2007a) that first presented the ideas on classifications as abstract structures of Groups, Semi- and groups, Monoids, and Boolean Algebra, as part of the discussions, in the note on enrichment exercises through a extension to rhotrices. −1 R−1 = b − h(R) d (1.6) (h(R))2 e Remark

In this section, we apply the definitions of relevant satisfying the properties R A I = I A R = R and −1 −1 abstract structures (Seymour and Marc, 2002) in the R A R = R A R = I , provided, h(R) ≠ 0 . It is simple development of the following new abstract structures of to show that R ,+ is a commutative group with rhotrices with respect to the binary operations of addition (+) and multiplication () given by equations (1.2) and (1.4) respectively. 0 ∗ 0 = 0 0 0 (1.7) R i n g o f r h o t r i c e s: Let R = R,+,A be an abstract 0 structure consisting of the set R of all real rhotrices of the same dimension as given by equation (1.1), together with the operations of addition (+) and multiplication () then R The multiplicative operation () defined (Ajibade, 2003) is a commutative ring of rhotrices. was noted with concern in the paper that multiplication of ∗ rhotrices could be defined in many ways. Following this, The unity element of the ring R is the identity rhotrix I, ∗ Sani (2004) proposed an alternative method for multipli- given by equation (1.5). The zero element of ring R is cation of rhotrices based on its rows and columns the zero rhotrix 0 given by equation (1.7). The units ele- vectors, as comparable to matrices. This alternative mul- ments in the ring R∗ are the nonzero heart rhotrices (that tiplication () approach was used in the paper to establish is the invertible rhotrices) given by the set: some relationships between rhotrices and matrices through an isomorphism. Thus, two methods for multipli- À a ¤ cation of rhotrices having the same dimension are Œ Œ (1.8) currently available in the literature. Each method provides U1 = Ã b c d : a,b,c,d,e∈ℜ and c ≠ 0‹ Œ Œ enabling environment to explore the usefulness of rho- Õ e › trices as an applicable tool for the creation of algebraic structures (Mohammed, 2007a) enrichment of matrix theory (Mohammed 2007a; Sani, 2007, 2008), and In addition, to the above properties of the ring R∗ , we development of special series and polynomial equations define a set ZD, consisting of all non-zero zero divisors 498 Int. J. Phys. Sci.

∗ ∗ in the ring R , by addition (+) and multiplication () then F is a Field of real rhotrices. À a ¤ Œ Œ PID of rhotrices: Let ZD = Ã b 0 d : a,b,d,e,0∈ℜ and at least one of a,b,c,d ≠ 0‹ Œ Œ Õ e › À a ¤ À a ¤ À 0 ¤ Œ Œ Œ Œ Œ Œ (1.9) P=Ã b 1 d : a,b,d,e∈Z‹∪Ã b −1 d : a,b,d,e∈Z‹∪Ã 0 0 0 ‹ Œ Œ Œ Œ Œ Œ e e 0 Further more, the sets Õ › Õ › Õ ›

À a ¤ be a set of some integer rhotrices and let ∗ Œ Œ (2.0) P = P , + , A J = Ã b 0 d : a , b , d , e ,0 ∈ ℜ ‹ Œ Œ be an abstract structure consisting of the set P, together Õ e › with the operations of addition (+) and multiplication () and ∗ then P is a Principal Ideal Domain of rhotrices.

À 0 ¤ Œ Œ UFD of rhotrices: Let k = Ã 0 0 0 ‹ Œ Œ Õ 0 › À a ¤ À 0 ¤ Œ Œ Œ Œ together with the operations of subtraction ‘-‘ and ‘o’, are U = Ã b c d : a,b,c, d,e ∈ Z and c ≠ 0 ‹ ∪ Ã 0 0 0 ‹ Œ Œ Œ Œ some of the ideals of ring R∗ . Õ e › Õ 0 › However, if R is a ring of integer rhotrices, then the only units in R is given by the set be a set of some integer rhotrices and let U ∗ = U,+, A À a ¤ be an abstract structure consisting of the set U, together Œ Œ with the operations of addition (+) and multiplication () U 2 = Ã b c d : a, b, c, d , e ∈ Ζ and c ∈ {1,-1} ‹ ∗ Œ Œ then U is a Unique Factorization Domain. Õ e ›

The irreducible elements in a ring of integer rhotrices is Conclusion given by the set of non-units integer rhotrices We have presented additional classifications of rhotrices À a ¤ as abstract structures. Rhotrices serve as an efficient and Œ Œ E 2 = Ã b c d : a , b, c, d , e ∈ Ζ and c ∉ {1,-1 } ‹ reliable tool in the study of infinite abstract structures as Œ Œ Õ e › demonstrated in this paper. The search for the applica- tion of rhotrices in the study of finite abstract structures offered an amazing area of interest for research. : Let R and ZD are as defined by equation ID of rhotrices (1.1) and equation (1.9) respectively and let ∗ D = (R − ZD),+,A be an abstract structure consis- ACKNOWLEDGEMENTS ting of some real rhotrices of the same dimension, together with the operations of addition (+) and multipli- My sincere thanks are due to my research supervisors, ∗ Professor G.U. Garba, Dr. B. Sani, and Dr. U.M. Makarfi cation () then D is an Integral Domain. for their helpful suggestions and encouragement. I also wish to thank my Employer, Ahmadu Bello University, Field of rhotrice: Let U1 be as given by equation (1.8) Zaria, Nigeria for funding this relatively new area of and let research.

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