Saved in:
Bibliographic Details
Main Authors: Bhattacharya, Rishabh, Kalsariya, Vikaskumar, Manwani, Naresh
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2602.19332
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908848360521728
author Bhattacharya, Rishabh
Kalsariya, Vikaskumar
Manwani, Naresh
author_facet Bhattacharya, Rishabh
Kalsariya, Vikaskumar
Manwani, Naresh
contents Model merging has emerged as a powerful paradigm for combining the capabilities of distinct expert models without the high computational cost of retraining, yet current methods are fundamentally constrained to homogeneous architectures. For GNNs, however, message passing is topology-dependent and sensitive to misalignment, making direct parameter-space merging unreliable. To bridge this gap, we introduce H-GRAMA (Heterogeneous Graph Routing and Message Alignment), a training-free framework that lifts merging from parameter space to operator space. We formalize Universal Message Passing Mixture (UMPM), a shared operator family that expresses heterogeneous GNN layers in a common functional language. H-GRAMA enables cross-architecture GNN merging (e.g., GCN to GAT) without retraining, retaining high specialist accuracy in most cases in compatible depth settings and achieving inference speedups of 1.2x to 1.9x over ensembles.
format Preprint
id arxiv_https___arxiv_org_abs_2602_19332
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Training-Free Cross-Architecture Merging for Graph Neural Networks
Bhattacharya, Rishabh
Kalsariya, Vikaskumar
Manwani, Naresh
Machine Learning
Model merging has emerged as a powerful paradigm for combining the capabilities of distinct expert models without the high computational cost of retraining, yet current methods are fundamentally constrained to homogeneous architectures. For GNNs, however, message passing is topology-dependent and sensitive to misalignment, making direct parameter-space merging unreliable. To bridge this gap, we introduce H-GRAMA (Heterogeneous Graph Routing and Message Alignment), a training-free framework that lifts merging from parameter space to operator space. We formalize Universal Message Passing Mixture (UMPM), a shared operator family that expresses heterogeneous GNN layers in a common functional language. H-GRAMA enables cross-architecture GNN merging (e.g., GCN to GAT) without retraining, retaining high specialist accuracy in most cases in compatible depth settings and achieving inference speedups of 1.2x to 1.9x over ensembles.
title Training-Free Cross-Architecture Merging for Graph Neural Networks
topic Machine Learning
url https://arxiv.org/abs/2602.19332