Interaction Strength and a Generalized Bak-Sneppen EvolutionModel

The Bak-Sneppen evolution model is generalized in terms of a new concept and quantity, interaction strength. Based on a quantitative definition, the interaction strength describes the strength of the interaction between the nearest neighbouring individuals in the model. Self-organized criticality is observed for the generalized model with ten different values of interaction strength. The gap equation governing the self-organization is derived. It is also found that the self-organized threshold depends on the value of the interaction strength.