BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20260525T171231EDT-8550z4e5H1@132.216.98.100 DTSTAMP:20260525T211231Z DESCRIPTION:Abstract\n\nLearning on graphs has emerged as a fundamental dir ection in machine learning\, as part of the broader field of geometric dee p learning\, which focuses on modeling the intricate structures and symmet ries underlying complex data.\n However\, existing standard paradigm of gra ph neural networks (GNNs) -- message passing neural networks (MPNNs) -- fa ce inherent limitations in terms of expressivity\, capacity\, flexibility\ , and generality.\n This thesis introduces a novel paradigm—learning on pse udo-coordinates—which provides not only enhanced expressive and representa tional power but also greater modeling flexibility.\n Pseudo-coordinates se rve as coordinate-like spatial representations that relax the strict const raints of conventional coordinate systems.\n They are particularly valuable for domains lacking canonical coordinate systems\, such as graphs and man ifolds.\n The main body of this thesis is composed of three principal studi es.\n The first study focuses on the design of graph Transformers\, represe nting a realization of the graph learning paradigm on pseudo-coordinates. \n In this work\, we introduce a powerful graph Transformer\, encompassing a novel pseudo-coordinate design and an advanced model architecture\, whic h demonstrates the superior effectiveness of graph learning on pseudo-coor dinates compared to the conventional message-passing paradigm.\n The second study investigates alternative approaches within this paradigm.\n We intro duce a novel graph convolutional operator defined on pseudo-coordinates\, leveraging the design of continuous convolutional kernels.\n The proposed g raph convolution is not only highly expressive but also generalizes many e xisting GNN formulations\, including but not limited to MPNNs and polynomi al spectral GNNs.\n More importantly\, it exhibits distinct characteristics from attention mechanisms in graph Transformers\, thereby expanding the d esign space for developing diverse and powerful graph neural architectures .\n The final study\, inspired by recent advances in Transformer-based mult imodal foundation models\, revisits the design of graph Transformers. We d emonstrate that\, contrary to the prevailing trend of introducing complex architectural modifications\, plain Transformer architectures—when equippe d with our proposed lightweight enhancements—can serve as highly effective graph learners. These enhancements are broadly applicable across domains and gracefully reduce to the original Transformer when necessary. This fin ding underscores the versatility of vanilla Transformer architectures and highlights their strong potential as a unified backbone for multimodal lea rning across language\, vision\, and graph domains.\n Collectively\, this t hesis underscores the broad potential of the graph learning on pseudo-coor dinates paradigm\, which offers not only strong expressivity and flexibili ty but also a promising pathway toward unifying graph learning with multim odal foundation models.\n DTSTART:20260114T193000Z DTEND:20260114T213000Z LOCATION:Room 603\, McConnell Engineering Building\, CA\, QC\, Montreal\, H 3A 0E9\, 3480 rue University SUMMARY:PhD defence of Liheng Ma – Towards More Expressive Graph Neural Net works via Learning on Pseudo-Coordinates URL:/ece/channels/event/phd-defence-liheng-ma-towards- more-expressive-graph-neural-networks-learning-pseudo-coordinates-370197 END:VEVENT END:VCALENDAR