Periodica Mathematica Hungarica

, Volume 67, Issue 2, pp 211–220

The regular graph of a commutative ring

Article

DOI: 10.1007/s10998-013-7039-1

Cite this article as:
Akbari, S. & Heydari, F. Period Math Hung (2013) 67: 211. doi:10.1007/s10998-013-7039-1
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Abstract

Let R be a commutative ring, let Z(R) be the set of all zero-divisors of R and Reg(R) = R\Z(R). The regular graph of R, denoted by G(R), is a graph with all elements of Reg(R) as the vertices, and two distinct vertices x, y ∈ Reg(R) are adjacent if and only if x+yZ(R). In this paper we show that if R is a commutative Noetherian ring and 2 ∈ Z(R), then the chromatic number and the clique number of G(R) are the same and they are 2n, where n is the minimum number of prime ideals whose union is Z(R). Also, we prove that all trees that can occur as the regular graph of a ring have at most two vertices.

Key words and phrases

regular graphNoetherian ringzero-divisorsclique numberchromatic number

Mathematics subject classification numbers

05C1505C2505C6913A13E05

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2013

Authors and Affiliations

  1. 1.Department of Mathematical SciencesSharif University of TechnologyTehranIran
  2. 2.Department of Mathematics, Karaj BranchIslamic Azad UniversityKarajIran