My work lies at the crossroads of machine learning, information theory, communications, and statistics, with the overarching goal of uncovering the mathematical foundations of modern AI. I am especially interested in how information theory—the mathematics of information—can explain and guide the behavior of learning systems.
I develop theoretical and methodological principles that shed light on the statistical properties of learning: from supervised and unsupervised learning to generalization, regularization, privacy mechanisms, transfer learning, and out-of-distribution detection. These ideas often translate into advances in computer vision, natural language processing, and beyond.
A growing strand of my research explores collaborative AI agents—how multiple intelligent systems (and humans) can reason together, communicate effectively, and make decisions collectively. This direction builds on my broader interest in the interaction between information, inference, and communication, and has applications in multi-turn dialogue, coordination, and trustworthy AI.
More recently, my work has focused on both theory and applications:
Statistical theory of information and learning: fundamental limits, generalization, transfer learning, information geometry, universal compression, bottleneck problems.
Trustworthy generative AI: detecting AI-generated content, hallucinations, membership inference attacks, privacy, fairness, robustness.
Deep learning methods: few-shot learning, clustering, classification, segmentation.
Applications in engineering, health, and science: from healthcare and energy systems to communications, molecular discovery, vision, and language.
This research explores how pragmatic reasoning can improve communication strategies in collaborative reinforcement learning (RL) and large language model (LLM)-based agents. We build on the Rational Speech Act (RSA) framework, which models communication as recursive social reasoning: speakers select messages that are informative from the listener’s perspective, while listeners interpret messages by considering the speaker’s goals.
We extend this to the Cooperative RSA (CRSA) framework, which adapts RSA to multi-agent, cooperative settings. By modeling nested beliefs and communicative goals across agents, CRSA provides a principled way to design effective communication in multi-turn dialogue scenarios. This line of research aims to bridge theory-driven pragmatic reasoning with modern RL and LLM-based systems to enable richer, more efficient collaboration among agents.
L. Estienne, G. Ben Zenou, N. Naderi, J. Cheung, P. Piantanida, "Collaborative RSA: Pragmatic Reasoning for Multi-Turn Dialog, " EMNLP 2025.
M. Vera, L. Rey Vega, P. Piantanida, "Collaborative Information Bottleneck, " IEEE Trans. on Information Theory 2019.
Security and reliability involve detecting AI-generated content, which can be misused to misinform, manipulate, or impersonate. Our research explores methods to identify synthetic text or media based on information-theoretic measures, helping systems recognize when content may be machine-generated.
M. Dubois, F. Yvon, P. Piantanida, "MOSAIC: Multiple Observers Spotting AI Content, " ACL 2025.
M. Dubois, F. Yvon, P. Piantanida, "How Sampling Affects the Detectability of Machine-written texts: A Comprehensive Study, " EMNLP 2025.
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Security and reliability involve detecting errors. AI models can make classification or regression errors, and may be overconfident even on unfamiliar inputs. Our research introduces Relative Uncertainty (REL-U), a data-driven measure that identifies misclassifications and large regression errors by learning patterns in model predictions. REL-U helps AI systems know when they might be wrong, improving safety and trustworthiness in applications like autonomous systems and medical AI.
E. Dadalto, C. Gomes, M. Romanelli, G. Pichler, P. Piantanida, "A Data-Driven Measure of Relative Uncertainty for Misclassification Detection, " ICLR 2024.
E. Dadalto, C. Gomes, M. Romanelli, G. Pichler, P. Piantanida, "Beyond the Norms: Detecting Prediction Errors in Regression Models, " ICML 2024.
F. Granese, M. Romanelli, D. Gorla, C. Palamidessi, P. Piantanida, "DOCTOR: A Simple Method for Detecting Misclassification Errors, " NeurIPS 2021.
Embodied AI agents interact closely with humans, collecting sensitive data from our environments, habits, and communications. Protecting this data requires understanding fundamental limits and certification processes, while careful system design ensures agents only use what is necessary.
E. Aubinais, E. Gassiat, P. Piantanida, "Fundamental Limits of Membership Inference Attacks on Machine Learning Models, " JMLR 2025.
E. Aubinais, P. Piantanida, E. Gassiat, "Membership Inference Risks in Quantized Models: A Theoretical and Empirical Study, " ArXiv 2025.
G. Del Grosso, G. Pichler, C. Palamidessi, P. Piantanida, "Fundamental Limits of Membership Inference Attacks on Machine Learning Models, " Neurocomputing 2023.
G. Pichler, M. Romanelli, L. R. Vega and P. Piantanida, "Perfectly Accurate Membership Inference by a Dishonest Central Server in Federated Learning," in IEEE Transactions on Dependable and Secure Computing, vol. 21, no. 4, pp. 4290-4296, July-Aug. 2024
Embedders transform objects—texts, images, molecules—into numerical representations for downstream tasks. Choosing the best embedder is challenging, as traditional evaluations rely on costly, task-specific benchmarks.
We propose a task-agnostic, self-supervised framework based on information sufficiency, which estimates how well one embedder preserves information relative to another. This allows ranking embedders without labeled data and predicting their downstream performance.
M. Darrin, P. Formont, I. Ben Ayed, J. CK Cheung , P. Piantanida, "When is an Embedding Model More Promising than Another?, " NeurIPS 2024.
L. Fosse, F. Béchet, B. Favre, G. Damnati, G. Lecorvé, M. Darrin, P. Formont, P. Piantanida, "Statistical Deficiency for Task Inclusion Estimation," ACL 2025.
M. Darrin, P. Formont, J. Cheung, P. Piantanida, "COSMIC: Mutual Information for Task-Agnostic Summarization Evaluation," ACL 2024 (SAC Award)
AI systems often struggle with subtle changes in input data and with efficiently capturing the information content in complex datasets. FIRE uses concepts from information geometry to make AI more robust: it measures the “distance” between predictions for original and slightly altered inputs using the Fisher-Rao Distance, ensuring the AI behaves consistently and reliably.
Meanwhile, understanding uncertainty and information is crucial for AI. KNIFE is a flexible, differentiable estimator of differential entropy and mutual information, allowing AI to adapt to changing data distributions and learn more effectively across tasks like domain adaptation, fair classification, and language model fine-tuning.
G. Pichler, P. Colombo, M. Boudiaf, G. Koliander, P. Piantanida, "A Differential Entropy Estimator for Training Neural Networks," ICML 2022.
P. Colombo, C. Clavel, P. Piantanida, "A Novel Estimator of Mutual Information for Learning to Disentangle Textual Representations," ACL 2021.
M. Picot, F. Messina, M. Boudiaf, F. Labeau, I. B. Ayed and P. Piantanida, "Adversarial Robustness Via Fisher-Rao Regularization," in IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 45, no. 3, pp. 2698-2710, March 2023.
E. Dadalto, C. Gomes, F. Alberge, P. Duhamel, P. Piantanida, "Igeood: An Information Geometry Approach to OOD Detection," ICLR 2022.
P. Colombo, C. Clavel, P. Piantanida, "InfoLM: A New Metric to Evaluate Summarization & Data2Text Generation, "AAAI 2022. (Outstanding S. Paper)
My earlier research, developed primarily before 2018, centered on network information theory and its wide-ranging applications. Within this field, I explored a broad spectrum of topics, contributing to fundamental limits and practical methods for signal acquisition, data compression, communication, decision-making, key generation, physical layer security, privacy, stochastic geometry, and index coding—with a particular emphasis on the principles of Shannon theory.
This work combined theoretical analysis with engineering applications, including:
Information theory for communications under uncertainty: state-dependent and compound networks, wireless communications, finite-length coding rates, degrees of freedom, hybrid ARQ schemes.
Interference, cooperation, and feedback: analysis of interference and cooperative networks, with models based on stochastic geometry for wireless systems.
Security, privacy, and key generation: statistical privacy via compression, secret key generation in communication networks, physical layer security, and vulnerabilities such as device attacks using covert channels.
Data mixing, caching, and index coding: the role of index coding in caching strategies and decentralized data shuffling.
Distributed decision-making and compression: interactive source coding and distributed binary decision problems under communication constraints.