2023/10/17 by Jamsheena, P., Chithra, A. V.
#05C25 #05C40 #05C50 #Combinatorics (math.CO) #Commutative Algebra (math.AC) #FOS: Mathematics #Rings and Algebras (math.RA)
paper · doi:10.48550/arxiv.2310.10999
Let R be a commutative ring with unity. The essential ideal graph ER of R is a graph in which the vertex set comprises of set of all nonzero proper ideals of R and two vertices I and K are adjacent if and only if I+K is an essential ideal. In this paper, we discuss the structure of an induced subgraph of the essential ideal graph of the ring ℤn as a \mathscrG-generalized join graph and thereby completely determine the structure of E_ℤn. Also, we prove a characterization of E_ℤn to be Laplacian integral in terms of the vertex-weighted Laplacian matrix of annihilating ideal graph of ℤn for n= ∏i=1k pi. Further, we discuss the eigenvalues of various matrices like adjacency matrix, Laplacian matrix, signless Laplacian matrix, and normalized Laplacian matrix of the induced subgraph of the essential ideal graph of ℤn. Finally, we obtain the upper bounds of spectral radius and algebraic connectivity of E_ℤn and compute the values of n for which these bounds are attained.