On cycles in intersection graph of rings
  Let $R$ be a commutative ring with non-zero identity. We describe all $C_3$- and $C_4$-free intersection graph of non-trivial ideals of $R$ as well as $C_n$-free intersection graph when $R$ is a reduced ring. Also, we shall describe all complete, regular and $n$-claw-free intersection graphs. Finally, we shall prove that almost all Artin rings $R$ have Hamiltonian intersection graphs. We show that such graphs are indeed pancyclic. 
Ali Azimi, Ahmad Erfanian, Mohammad Farrokhi Derakhshandeh Ghouchan   and Nesa Hoseini
math.AC