Antonio Longa

I am Antonio Longa, a Postdoctoral Researcher at UiT The Arctic University of Norway, where I work with the Northernmost GraphML Group under the supervision of Filippo Maria Bianchi. I am also a member of ELLIS.

Previously, I was an Assistant Professor at the University of Trento, working in the Structured Machine Learning Group led by Andrea Passerini. I earned my Ph.D. with honors from the University of Trento and Fondazione Bruno Kessler, working in the MobS Lab under the supervision of Bruno Lepri.

My research focuses on Graph Machine Learning, Temporal Graphs, Relational Deep Learning, and Complex Systems, with interests in both theoretical foundations and real-world applications, including energy systems and materials science.

I am always happy to discuss science and research, so feel free to get in touch :)

antonio.longa@uit.no

Blog Posts

Short research notes, tutorials, and explainers on Graph Machine Learning, Temporal Graphs, Network Science, and related topics.

Overview of egocentric temporal neighborhood generation

Link Representation · Expressive GNNs

When Links Look the Same: Expressive GNNs for Link Representation

Link representation with graph neural networks: from understanding theoretical expressiveness, to comparing subgraph-based and heuristic methods, to bridging practical link prediction with principled multi-node representation learning.

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Relational database represented as a heterogeneous graph with learned meta-path patterns

Meta-Paths · Heterogeneous GNNs

On the Importance of Meta-Paths: a Self-Explainable multi-relational GNN

Why meta-paths matter in heterogeneous graph neural networks: from MP-GNN, which learns informative relation chains automatically, to MPS-GNN, which extends them with statistics over repeated relational patterns.

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Overview of structural encoding

Graph Transformers · Structural Encoding

Beyond Random Walks: Simple Path Structural Encoding for Graph Transformers

A clear look at Simple Path Structural Encoding: why random-walk edge encodings can miss cyclic structure, how simple path counts improve graph transformer representations, and what the results show on molecular, long-range, and graph benchmark tasks.

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RelSC graph construction for software performance prediction

Graph Regression · Software Performance

Graph Regression for Software Performance: RelSC Benchmarks for Runtime Prediction

A benchmark for predicting Java execution time from source-code graphs, combining syntax, control flow, and data flow in homogeneous and multi-relational graph representations.

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Overview of egocentric temporal neighborhood generation

Temporal Graphs · Network Generation

From Temporal Motifs to Community-Aware Temporal Graph Generation

A concise research story on egocentric temporal neighborhoods: from mining temporal motifs, to generating surrogate temporal networks, to modeling communities and higher-order interactions.

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Publications

A Benchmark Dataset for Graph Regression with Homogeneous and Multi-Relational Variants P. Samoaa, M. Vukojevic, M.H. Chehreghani, A. Longa
DMLR 2026 2026
Bridging Theory and Practice in Link Representation with Graph Neural Networks V. Lachi, F. Ferrini, A. Longa, B. Lepri, A. Passerini, M. Jaeger
NeurIPS 2025 (Spotlight) 2025
Simple Path Structural Encoding for Graph Transformers L. Airale, A. Longa, M. Rigon, A. Passerini, R. Passerone
ICML 2025 2025
Reconsidering Faithfulness in Regular, Self-Explainable and Domain Invariant GNNs S. Azzolin, A. Longa, S. Teso, A. Passerini
ICLR 2025 2025
Explaining the Explainers in Graph Neural Networks: a Comparative Study A. Longa, S. Azzolin, G. Santin, G. Cencetti, P. Liò, B. Lepri, A. Passerini
ACM Computing Surveys 2025
Community Aware Temporal Network Generation N.A. Girardini, A. Longa, G. Trebucchi, G. Cencetti, A. Passerini, B. Lepri
Applied Network Science 2025
A Self-Explainable Heterogeneous GNN for Relational Deep Learning F. Ferrini, A. Longa, A. Passerini, M. Jaeger
TMLR 2025 2025
A Temporal Multipartite Network for News Articles Insights Extraction A. Longa, M. Luca; G. Lopez, J. Kaul
AI4B 2024
Patterns in temporal networks with higher-order egocentric structures B. Arregui-Garcia, A. Longa, Q.F. Lotito, S. Meloni, G. Cencetti
Entropy 2024
Putting Context in Context: the Impact of Discussion Structure on Text Classification N. Penzo, A. Longa, B. Lepri, S. Tonelli, M. Guerrini
EACL 2024 2024
How are You Really Doing? Dig into the Wheel of Emotions with Large Language Models M. Luca; G. Lopez, A. Longa, J. Kaul
AI4B 2024
A Simple and Expressive Graph Neural Network Based Method for Structural Link Representation V. Lachi, F. Ferrini, A. Longa, B. Lepri, A. Passerini
ICML 2024 Workshop GRaM 2024
Sheaf Diffusion Goes Nonlinear: Enhancing GNNs with Adaptive Sheaf Laplacians O. Zaghen, A. Longa, S. Azzolin, L. Telyatnikov, A. Passerini, P. Liò
ICML 2024 Workshop GRaM 2024
A unified active learning framework for annotating graph data for regression task P. Samoaa, L. Aronsson, A. Longa, P. Leitner, M.H. Chehreghani
Engineering Applications of Artificial Intelligence 2024
Meta-Path Learning for Multi-relational Graph Neural Networks F. Ferrini, A. Longa, A. Passerini, M. Jaeger
Learning on Graphs 2023 (Oral) 2023
A Simple Latent Variable Model for Graph Learning and Inference M. Jaeger, A. Longa, S. Azzolin, O. Schulte, A. Passerini
Learning on Graphs 2023 2023
Understanding Social Interactions via Temporal Network Analysis A. Longa
Ph.D. Thesis 2023
Graph Neural Networks for Temporal Graphs: State of the Art, Challenges, and Opportunities A. Longa, V. Lachi, G. Santin, M. Bianchini, B. Lepri, P. Liò, F. Scarselli, A. Passerini
TMLR 2023 2023
Global Explainability of GNNs via Logic Combination of Learned Concepts S. Azzolin, A. Longa, P. Barbiero, P. Liò, A. Passerini
ICLR 2023 2022
Emotion Analysis Using Multilayered Networks for Graphical Representation of Tweets A. Nguyen, A. Longa, M. Luca, J. Kaul, G. Lopez
IEEE Access 2022
TEP-GNN: Accurate Execution Time Prediction of Functional Tests using Graph Neural Networks H. P. Samoaa, A. Longa, M. Mohamad, M. H. Chehreghani, P. Leitner
PROFES 2022 2022
Generating Synthetic Mobility Networks with Generative Adversarial Networks G. Mauro, M. Luca, A. Longa, B. Lepri, L. Pappalardo
EPJ Data Science 2022
An Efficient Procedure for Mining Egocentric Temporal Motifs A. Longa, G. Cencetti, B. Lepri, A. Passerini
ECML PKDD DAMI 2022
Digital Proximity Tracing on Empirical Contact Networks for Pandemic Control G. Cencetti, G. Santin, A. Longa, E. Pigani, A. Barrat, C. Cattuto, S. Lehmann, M. Salathé, B. Lepri
Nature Communications 2021

Talks

Projects

Chem Interactions

Interactive platform for exploring ligand–metal–solvent interactions and discovering MOFs using FAIR-MOF data-driven recommendations

Pytorch Geometric Tutorials

Collections of video tutorials and material for the implementation of GDL in PyG

Advanced Pytorch Geometric Tutorials

Collections of video tutorials and material for the implementation of advanced techniques in PyG

Egocentric Temporal Motifs Miner (ETMM)

Blog post presenting a novel mining technique based on the notion of Egocentric Temporal Motifs.

AI Trento Journal club

The AI Trento Journal Club is an open science initiative aiming to discuss and speculate about various topics of Machine Learning, Artificial Intelligence, and Computer Science.

LOG meetup Trento

Trento meetup of the Learning on Graph Conference, an annual research conference that covers areas broadly related to machine learning on graphs and geometry.

Teaching

Scientific Programming - Programming - 2025-2026

Master of Data Science - Trento University

Scientific Programming - Programming - 2024-2025

Master of Data Science - Trento University

Scientific Programming - Programming - 2023-2024

Master of Data Science - Trento University

Scientific Programming - Programming - 2022-2023

Master of Data Science - Trento University

Machine Learning - Module I - 2021 - 2022

Master of Science in Artificial Intelligence Systems - Trento University
Part 1 (Sklearn)

Machine Learning 2021 - 2022

Master of Science in Computer Science - Trento University
Part 1 (Sklearn) - Part 1 (Tensorflow)

Informatica 2020 - 2021

Scienze e Tecnologie Biomolecolari - Università degli Studi di Trento

Review

  • NeurIPS
  • KDD (top reviewer)
  • ICML
  • ICLR
  • WWW
  • ECML
  • TMLR
  • Neural Networks
  • Artificial Intelligence
  • ACM Computing Surveys
  • Physica A: Statistical Mechanics and its Applications
  • Machine Learning
  • MLG