Periodic and Weakly Periodic Ground States for the $\lambda$-Model on   Cayley Tree
  In this paper we consider the $\lambda$-model on the Cayley tree of order two. We describe periodic and weakly periodic ground states for the considered model. 
Farrukh Mukhamedov, Chin Hee Pah, Muzaffar Rahmatullaev, Hakim Jamil
math-ph cond-mat.stat-mech math.MP