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Lorenz Kummer

4 accepted papers

2026

A Unifying Relational Perspective on Expressive Lottery Tickets

ICML 2026spotlight

Graph neural networks (GNNs) are widely used, but how parameter sparsity affects the expressivity of relational (RGNNs) and temporal (TGNNs) variants is poorly understood. The Strong Expressive Lottery Ticket Hypothesis (SELTH) posits the existence of sparse GNNs that preserve Weisfeiler-Leman (WL) …

Cited by 0SourceScholar
2025

Crossfire: An Elastic Defense Framework for Graph Neural Networks Under Bit Flip Attacks

AAAI 2025technical

Bit Flip Attacks (BFAs) are a well-established class of adversarial attacks, originally developed for Convolutional Neural Networks within the computer vision domain. Most recently, these attacks have been extended to target Graph Neural Networks (GNNs), revealing significant vulnerabilities. This n…

2025

On the Relationship Between Robustness and Expressivity of Graph Neural Networks

AISTATS 2025poster

We investigate the vulnerability of Graph Neural Networks (GNNs) to bit-flip attacks (BFAs) by introducing an analytical framework to study the influence of architectural features, graph properties, and their interaction. The expressivity of GNNs refers to their ability to distinguish non-isomorphic…

Cited by 2SourceScholar
2025

Weisfeiler and Leman Go Gambling: Why Expressive Lottery Tickets Win

ICML 2025poster

The lottery ticket hypothesis (LTH) is well-studied for convolutional neural networks but has been validated only empirically for graph neural networks (GNNs), for which theoretical findings are largely lacking. In this paper, we identify the expressivity of sparse subnetworks, i.e. their ability to…

Cited by 0SourcePDFScholar