Some results on the comaximal ideal graph of a commutative ring

Let R be a commutative ring with unity. The comaximal ideal graph of R, denoted by \mathcal{C}(R), is a graph whose vertices are the proper ideals of R which are not contained in the Jacobson radical of R, and two vertices I_1 and I_2 are adjacent if and only if I_1 +I_2 = R. In this paper, we classify all comaximal ideal graphs with finite independence number and present a formula to calculate this number. Also, the domination number of \mathcal{C}(R) for a ring R is determined. In the last section, we introduce all planar and toroidal comaximal ideal graphs. Moreover, the commutative rings with isomorphic comaximal ideal graphs are characterized. In particular we show that every finite comaximal ideal graph is isomorphic to some \mathcal{C}(\mathbb{Z}_n).

Some results on the comaximal ideal graph of a commutative ring Keywords:

Comaximal ideal graph , Genus of graph , Domination Number , Independence number