<p>Exponential random graph models (ERGMs) are flexible probability models allowing edge dependency. However, it is known that to a first-order approximation, many ERGMs behave like Erdös-Rényi random graphs, where edges are independent. In this paper, to distinguish ERGMs from Erdös-Rényi random graphs, we consider second-order approximations of ERGMs using two-stars and triangles. We prove that the second-order approximation indeed achieves second-order accuracy in the triangle-free case. The new approximation is formally obtained by the Hoeffding decomposition and rigorously justified using Stein’s method.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Second-order approximation of exponential random graph models

  • Wen-Yi Ding,
  • Xiao Fang

摘要

Exponential random graph models (ERGMs) are flexible probability models allowing edge dependency. However, it is known that to a first-order approximation, many ERGMs behave like Erdös-Rényi random graphs, where edges are independent. In this paper, to distinguish ERGMs from Erdös-Rényi random graphs, we consider second-order approximations of ERGMs using two-stars and triangles. We prove that the second-order approximation indeed achieves second-order accuracy in the triangle-free case. The new approximation is formally obtained by the Hoeffding decomposition and rigorously justified using Stein’s method.