In the 25th International Conference on Autonomous Agents and Multi-Agent Systems (AAMAS2026)

During social movements, protesters need to gather with limited communication means and limited knowledge other than what they observe in their direct surroundings. We propose BeWater, a fully distributed walking protocol that achieves gathering thanks to city information like street length, number of restaurants, number of lanes, or street names. Even though using only one of these observables performs poorly, we show that combining them in more advanced tactics rapidly leads to groups of significant sizes. To do so, our work leverages OpenStreetMap data to perform experiments on several real-world cities.

arxiv url to come.

Communications of the ACM Blog

Instead of researching topics that serve the Machine, Matthieu Latapy advocates for more research on ecological and social movement needs.

Full text available here

In France International Conference on Complex Systems (FrCCS), 2025

We propose a method to detect communities in multi-relational networks, based on a graph neural network pipeline. The method allows to target areas where communities are consensual over the different modes of the network, which are processed as different networks in the pipeline. This is done by combining the outcomes of multiple simple Graph Neural Networks, applied on each of the graphs representing different forms of interactions between users of the social platform. The method is validated on a synthetic benchmark, as a first step for further improvements. In particular, the flexible architecture of the pipeline allows to swap its subparts and create variants of community detection.

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In IEEE International Conference on Data Mining (ICDM), 2025

Detecting anomalies in link streams that represent various kinds of interactions is an important research topic with crucial applications. Because of the lack of ground truth data, proposed methods are mostly evaluated through their ability to detect randomly injected links. In contrast with most proposed methods, that rely on complex approaches raising computational and/or interpretability issues, we show here that trivial graph features and classical learning techniques are sufficient to detect such anomalies extremely well. This basic approach has very low computational costs and it leads to easily interpretable results. It also has many other desirable properties that we study through an extensive set of experiments. We conclude that detection methods should now target more complex kinds of anomalies.

arxiv url to come

In International Conference on Complex Networks. Cham: Springer Nature Switzerland, 2025 (CompleNet2025)

We improve a flocking model on street networks introduced in a previous paper. We expand the field of vision of walkers, making the model more realistic. Under such conditions, we obtain groups of walkers whose gathering times and robustness to break ups are better than previous results. We explain such improvements because the alignment rule with vision guaranties walkers do not split into divergent directions at intersections anymore, and because the attraction rule with vision gathers distant groups. This paves the way to a better understanding of events where walkers have collective decentralized goals, like protests.

https://arxiv.org/pdf/2505.21585

PLoS One, e0338486, 20 (12), 2025

This study explores a model for the co-evolution of opinions and groups, related to opinion polarization and group identity in opinion dynamics. While traditional models focus on pairwise interactions, we incorporate the notion of groups thereby allowing agents to identify other agents as in-group or out-group. By modifying key parameters we examine how understanding interactions as in-group or out-group affects the convergence or divergence of opinions. Our findings reveal that attitude towards out-group plays a leading role in the polarization of such systems, while in-group interactions can temper extreme opinion shifts or even fragment groups. This model offers an understanding of the complex interplay between group identification and polarization, providing a contribution to ongoing debates about segregation and sectarianism in public and private spheres.

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Jeudi 22 janvier 2026 à 14h en salle 26-00/534

Lien vers PIQ

Guillaume Chelius, directeur du Programme Inria Quadrant (PIQ), viendra nous parler de ce programme très spécifique de soutien aux démarches de recherche à risque et à impact dans le numérique. Le programme, ouvert depuis fin 2024, accompagne et finance des scientifiques désireux d’engager des projets de recherche à risque et à impact dans le domaine des sciences et technologies du numérique, de ses fondements à ses usages. PIQ s’adresse à tous les scientifiques issus de l’ensemble les établissements publics de l’Enseignement Supérieur et de la recherche, chercheurs, enseignants chercheurs, ingénieurs de recherche. PIQ est ouvert à toute la communauté scientifique académique. PIQ accompagne des projets orientés « porteurs », de durée variable, de six mois à plus de trois ans, et sur des budgets pouvant aller de quelques dizaines milliers d’euros à plus d’un million d’euros. Aucun format n’est imposé. Durant cette session, Guillaume nous présentera le positionnement particulier du programme, la manière dont il s’empare de ces notions de risque et d’impact, ainsi que ses modalités spécifiques d’opération, son processus de candidature et l’ingénierie projet qu’il déploie. Les actualités du programme seront abordées, notamment à travers des projets accompagnés.

Jeudi 18 décembre 2025 à 14h en salle 26-00/534

Depuis une vingtaine d’années, la pratique du blocage prend une place croissante dans les mouvements sociaux à l’échelle internationale, des mobilisations altermondialistes au mouvement pro-démocratie à Hong Kong, en passant par les Gilets Jaunes et l’appel « Bloquons tout ! » en France. Si ce mode d’action tranche par sa nouveauté, il s’inscrit également dans une longue histoire de subversion par la perturbation des flux, dont on trouve déjà des manifestations au XVIIe siècle. Cet exposé étudiera la manière dont ont progressivement émergé des tactiques fondées sur l’idée que le pouvoir devait être attaqué dans ses réseaux techniques et ses infrastructures, du XIXe siècle à nos jours.

Jeudi 10 Juillet 2025 à 14h00 en salle 26-00/428

Slides

Several recent initiatives have been proposing new directions for research practices and their operations in the computer science community, from updated codes of conduct that clarify the use of AI-assisted tools to the inclusion of ethical statements and the organisation of working groups on the environmental footprint of digitalisation. In this talk, we will discuss what frameworks are needed to help describe the sense of engagement and accountability with which the practitioner of a computing-related area may be confronted, and guide one to think about the incidence of technical realisations beyond techno-centric contributions. We will share examples from current research projects, including the recent organisation of a session at the 2025 Internet Governance Forum, and teaching practices to illustrate some concrete scenarios.

Jeudi, 12 Juin 2025 à 11h en salle 24-25/405

Several recent initiatives have been proposing new directions for research practices and their operations in the computer science community, from updated codes of conduct that clarify the use of AI-assisted tools to the inclusion of ethical statements and the organisation of working groups on the environmental footprint of digitalisation. In this talk, we will discuss what frameworks are needed to help describe the sense of engagement and accountability with which the practitioner of a computing-related area may be confronted, and guide one to think about the incidence of technical realisations beyond techno-centric contributions. We will share examples from current research projects, including the recent organisation of a session at the 2025 Internet Governance Forum, and teaching practices to illustrate some concrete scenarios.