Mitigating Homophily Disparity in Graph Anomaly Detection: A Scalable and Adaptive Approach

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Hauptverfasser: Liu, Yunhui, Xie, Qizhuo, Chen, Yinfeng, Jin, Xudong, Zheng, Tao, Chong, Bin, He, Tieke
Format: Preprint
Veröffentlicht: 2026
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author Liu, Yunhui
Xie, Qizhuo
Chen, Yinfeng
Jin, Xudong
Zheng, Tao
Chong, Bin
He, Tieke
author_facet Liu, Yunhui
Xie, Qizhuo
Chen, Yinfeng
Jin, Xudong
Zheng, Tao
Chong, Bin
He, Tieke
contents Graph anomaly detection (GAD) aims to identify nodes that deviate from normal patterns in structure or features. While recent GNN-based approaches have advanced this task, they struggle with two major challenges: 1) homophily disparity, where nodes exhibit varying homophily at both class and node levels; and 2) limited scalability, as many methods rely on costly whole-graph operations. To address them, we propose SAGAD, a Scalable and Adaptive framework for GAD. SAGAD precomputes multi-hop embeddings and applies reparameterized Chebyshev filters to extract low- and high-frequency information, enabling efficient training and capturing both homophilic and heterophilic patterns. To mitigate node-level homophily disparity, we introduce an Anomaly Context-Aware Adaptive Fusion, which adaptively fuses low- and high-pass embeddings using fusion coefficients conditioned on Rayleigh Quotient-guided anomalous subgraph structures for each node. To alleviate class-level disparity, we design a Frequency Preference Guidance Loss, which encourages anomalies to preserve more high-frequency information than normal nodes. SAGAD supports mini-batch training, achieves linear time and space complexity, and drastically reduces memory usage on large-scale graphs. Theoretically, SAGAD ensures asymptotic linear separability between normal and abnormal nodes under mild conditions. Extensive experiments on 10 benchmarks confirm SAGAD's superior accuracy and scalability over state-of-the-art methods.
format Preprint
id arxiv_https___arxiv_org_abs_2603_08137
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Mitigating Homophily Disparity in Graph Anomaly Detection: A Scalable and Adaptive Approach
Liu, Yunhui
Xie, Qizhuo
Chen, Yinfeng
Jin, Xudong
Zheng, Tao
Chong, Bin
He, Tieke
Machine Learning
Graph anomaly detection (GAD) aims to identify nodes that deviate from normal patterns in structure or features. While recent GNN-based approaches have advanced this task, they struggle with two major challenges: 1) homophily disparity, where nodes exhibit varying homophily at both class and node levels; and 2) limited scalability, as many methods rely on costly whole-graph operations. To address them, we propose SAGAD, a Scalable and Adaptive framework for GAD. SAGAD precomputes multi-hop embeddings and applies reparameterized Chebyshev filters to extract low- and high-frequency information, enabling efficient training and capturing both homophilic and heterophilic patterns. To mitigate node-level homophily disparity, we introduce an Anomaly Context-Aware Adaptive Fusion, which adaptively fuses low- and high-pass embeddings using fusion coefficients conditioned on Rayleigh Quotient-guided anomalous subgraph structures for each node. To alleviate class-level disparity, we design a Frequency Preference Guidance Loss, which encourages anomalies to preserve more high-frequency information than normal nodes. SAGAD supports mini-batch training, achieves linear time and space complexity, and drastically reduces memory usage on large-scale graphs. Theoretically, SAGAD ensures asymptotic linear separability between normal and abnormal nodes under mild conditions. Extensive experiments on 10 benchmarks confirm SAGAD's superior accuracy and scalability over state-of-the-art methods.
title Mitigating Homophily Disparity in Graph Anomaly Detection: A Scalable and Adaptive Approach
topic Machine Learning
url https://arxiv.org/abs/2603.08137