One Router to Route Them All: Homogeneous Expert Routing for Heterogeneous Graph Transformers

Fuente: arXiv
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Main Authors: Shakirov, Georgiy, Arakelov, Albert
Format: Preprint
Published: 2025
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author Shakirov, Georgiy
Arakelov, Albert
author_facet Shakirov, Georgiy
Arakelov, Albert
contents A common practice in heterogeneous graph neural networks (HGNNs) is to condition parameters on node/edge types, assuming types reflect semantic roles. However, this can cause overreliance on surface-level labels and impede cross-type knowledge transfer. We explore integrating Mixture-of-Experts (MoE) into HGNNs--a direction underexplored despite MoE's success in homogeneous settings. Crucially, we question the need for type-specific experts. We propose Homogeneous Expert Routing (HER), an MoE layer for Heterogeneous Graph Transformers (HGT) that stochastically masks type embeddings during routing to encourage type-agnostic specialization. Evaluated on IMDB, ACM, and DBLP for link prediction, HER consistently outperforms standard HGT and a type-separated MoE baseline. Analysis on IMDB shows HER experts specialize by semantic patterns (e.g., movie genres) rather than node types, confirming routing is driven by latent semantics. Our work demonstrates that regularizing type dependence in expert routing yields more generalizable, efficient, and interpretable representations--a new design principle for heterogeneous graph learning.
format Preprint
id arxiv_https___arxiv_org_abs_2511_07603
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle One Router to Route Them All: Homogeneous Expert Routing for Heterogeneous Graph Transformers
Shakirov, Georgiy
Arakelov, Albert
Machine Learning
Artificial Intelligence
I.2.6
A common practice in heterogeneous graph neural networks (HGNNs) is to condition parameters on node/edge types, assuming types reflect semantic roles. However, this can cause overreliance on surface-level labels and impede cross-type knowledge transfer. We explore integrating Mixture-of-Experts (MoE) into HGNNs--a direction underexplored despite MoE's success in homogeneous settings. Crucially, we question the need for type-specific experts. We propose Homogeneous Expert Routing (HER), an MoE layer for Heterogeneous Graph Transformers (HGT) that stochastically masks type embeddings during routing to encourage type-agnostic specialization. Evaluated on IMDB, ACM, and DBLP for link prediction, HER consistently outperforms standard HGT and a type-separated MoE baseline. Analysis on IMDB shows HER experts specialize by semantic patterns (e.g., movie genres) rather than node types, confirming routing is driven by latent semantics. Our work demonstrates that regularizing type dependence in expert routing yields more generalizable, efficient, and interpretable representations--a new design principle for heterogeneous graph learning.
title One Router to Route Them All: Homogeneous Expert Routing for Heterogeneous Graph Transformers
topic Machine Learning
Artificial Intelligence
I.2.6
url https://arxiv.org/abs/2511.07603