Eur. Phys. J. B (2017) 90: 220
https://doi.org/10.1140/epjb/e2017-80022-y

Regular Article

Critical behavior of a stochastic anisotropic Bak–Sneppen model

¹ School of Computer and Communication Engineering, Zhengzhou University of Light Industry, Zhengzhou, P.R. China
² Complexity Science Center, Central China Normal University, Wuhan, P.R. China
³ National Engineering Laboratory for Technology of Big Data Applications in Education, Central China Normal University, Wuhan, P.R. China

^a e-mail: hanjihui@zzuli.edu.cn
^b e-mail: liw@mail.ccnu.edu.cn

Received: 10 January 2017
Received in final form: 20 September 2017
Published online: 13 November 2017

Abstract

In this paper we present our study on the critical behavior of a stochastic anisotropic Bak–Sneppen (saBS) model, in which a parameter α is introduced to describe the interaction strength among nearest species. We estimate the threshold fitness f_c and the critical exponent τ_r by numerically integrating a master equation for the distribution of avalanche spatial sizes. Other critical exponents are then evaluated from previously known scaling relations. The numerical results are in good agreement with the counterparts yielded by the Monte Carlo simulations. Our results indicate that all saBS models with nonzero interaction strength exhibit self-organized criticality, and fall into the same universality class, by sharing the universal critical exponents.