Diffusion-based generative graph models have been proven effective in generating high-quality small graphs. However, they need to be more scalable for generating large graphs containing thousands of nodes desiring graph statistics. In this work, we propose EDGE, a new diffusion-based generative graph model that addresses generative tasks with large graphs. To improve computation efficiency, we encourage graph sparsity by using a discrete diffusion process that randomly removes edges at each time step and finally obtains an empty graph. EDGE only focuses on a portion of nodes in the graph at each denoising step. It makes much fewer edge predictions than previous diffusion-based models. Moreover, EDGE admits explicitly modeling the node degrees of the graphs, further improving the model performance. The empirical study shows that EDGE is much more efficient than competing methods and can generate large graphs with thousands of nodes. It also outperforms baseline models in generation quality: graphs generated by our approach have more similar graph statistics to those of the training graphs.

本文提出了一种名为EDGE的新型扩散生成图模型，通过在每个时间步骤随机删除边并最终获得空图的离散扩散过程，鼓励图结构的稀疏性，使其更有效率地生成包含上千节点的大型图，并明确将图中节点度数建模，与基线模型相比，生成的图像质量更高，具有更相似的图统计特征。

离散扩散模型下的高效度指导图生成