Bayes-Duality 2026 Schedule
Morning Session (chair: TBA)
Afternoon Session (chair: TBA)
Morning Session (chair: TBA)
Afternoon Session (chair: TBA)
Morning Session (chair: Thomas Möllenhoff)
Abstract: TBA
Bio: TBA
Abstract: In this talk, I will cover three distinct non-stationary learning settings and propose algorithms to address the challenges unique to each. First, I will discuss streaming RL and show how learning representations online can improve the sample efficiency of streaming RL algorithms. Second, I will consider various forms of distribution shifts that occur in both supervised learning and RL and propose a very simple loss-smoothing technique for stable adaptation to distributional shifts. Finally, I will discuss the problem of continual pre-training and how to continually learn/unlearn as the data distribution changes over the years, including not only additions but also deletions of data.
Bio: Sarath Chandar is an Associate Professor at Polytechnique Montreal, where he leads the Chandar Research Lab. He is also a core faculty member at Mila, the Quebec AI Institute. Sarath holds a Canada CIFAR AI Chair and the Canada Research Chair in Lifelong Machine Learning. His research interests include lifelong learning, deep learning, optimization, reinforcement learning, natural language processing, and AI for Science. To promote research in lifelong learning, Sarath created the Conference on Lifelong Learning Agents (CoLLAs) in 2022.
Afternoon Session (chair: Thomas Möllenhoff)
Abstract: I will outline challenges and shifting paradigms in continual learning (CL) within the context of large models. I emphasize stability-plasticity dilemma that CL must balance catastrophic forgetting with adapting to new knowledge. By four key issues, I will show how conventional setups fail to ensure fair computational comparisons and explore the complexities of managing CL across heterogeneous network architectures. Furthermore, I present evidence that for large foundation models, knowledge acquisition and adaptation become more dominant challenges than forgetting itself. Ultimately, I argue that advancing large-scale CL requires a shift toward innovative approaches, such as decentralized collaboration frameworks and modular memory systems
Bio: I received my B.S. (2003) and M.S. (2008) in Electrical and Computer Engineering from Seoul National University, and my Ph.D. (2015) from the University of Maryland, College Park, under the supervision of Prof. Larry S. Davis. Since 2024, I have been an Associate Professor in the Department of Electrical and Computer Engineering at SNU. During my Ph.D., I did research internships at the US Army Research Lab (2012), Adobe Research (2013), Disney Research Pittsburgh (2014), and Microsoft Research Redmond (2014). I subsequently worked as a Research Scientist at the Allen Institute for AI (AI2, Seattle, 2016–2018) and at Comcast Applied AI Research (Washington, D.C., 2015–2016), and held faculty positions as Assistant Professor at GIST (2018–2022) and Associate Professor at Yonsei University (2022–2024). I serve as an Area Chair for NeurIPS, ICML, ICLR, CVPR, WACV, AAAI (Senior PC), and ICRA, and as an Associate Editor for IEEE Transactions on PAMI and IJCV. My research focuses on visual understanding for edge devices and home robots, and on image/video visual recognition under computational and data-efficiency constraints.
Morning Session (chair: Kenichi Bannai)
Emtiyaz Khan: A short summary of the Bayes Duality Project (60 min)
Abstract:I will give a short summary of the goals and achievements of the Bayes-duality project and the developed of adaptive Bayesian intelligence.
Emtiyaz Khan & Nico Daheim: PoCo and Beyond SVRG (30 min)
Abstract: In this work we show how an existing variance reduction technique called SVRG can be generalized using Posterior Correction. We use the generalization to derive a new Adam-like method that works well for deep learning.
Bio: Nico Daheim is a final year ELLIS PhD student at TU Darmstadt and ETH Zürich. His research focuses on using Bayesian methods to improve LLMs, for example, using variational training, model merging, and uncertainty-aware language generation methods.
Thomas Möllenhoff: IVON + Edge of Stability (15 min)
Abstract: Variational learning with an Improved Variational Online Newton method (IVON) can consistently match or outperform Adam for neural networks such as GPT-2. IVON’s computational costs are nearly identical to Adam but computes Bayesian weight uncertainty on top for free, which is useful in many downstream tasks. The talk gives a short overview of several projects which have been using the IVON optimizer since its publication two years ago. In particular, I will talk about a theoretical analysis of IVON good performance via an approach called Edge of Stability.
Bio: Thomas Moellenhoff is the deputy team leader of the Adaptive Bayesian Intelligence Team at the RIKEN Center for Advanced Intelligence Project in Tokyo, Japan. Previously, he was a postdoctoral researcher with Emtiyaz Khan at RIKEN AIP, and he obtained his PhD under the supervision of Daniel Cremers at the Technical University of Munich. His current research interests are at the intersection of optimization and Bayesian deep learning. Personal website: https://moellenh.github.io
Paul Subarnaduti & Siddharth Swaroop: Fast and Slow VCL (15 min)
Abstract:Continual learning remains a major challenge for modern deep networks, partly because commonly used optimizers lack inherent mechanisms for continual adaptation. One such natural mechanism is ‘fast and slow adaptation’ to balance stability and plasticity. This mechanism has deep roots in neuroscience and biology, but there is no consensus on how to best incorporate it in commonly used optimizers. Here, we show that this can be easily done via the VCL framework, where past posteriors are used as priors in the future. Our key idea is to incorporate slow adaptation via merging of past posteriors to slow down the drift in the knowledge as learning progresses. The merged posterior is then used as the prior in the VCL update to implement the fast-weight updates. These steps can be seamlessly implemented in the IVON optimizer, whose form and costs are nearly identical to that of Adam. We call this new optimizer the Continual IVON (CoVON) optimizer and show that it not only consistently improves over existing VCL optimizers, but also performs better than other weight-regularization strategies across domain-incremental learning, continual pre-training, and fine-tuning of large language models.
Bio: Fourth year PhD student at the Open World Lifelong Machine Learning Lab (OWL-ML) headed by Prof. Dr. Martin Mundt at the University of Bremen.
Afternoon Session (chair: Emtiyaz Khan)
Adrian R. Minut: EVON (15 min)
Abstract: EVON is a method for learning richer uncertainty in neural networks without the cost of a full covariance model. The main idea is to use the eigenspace learned by SOAP, run a diagonal variational method like IVON in that rotated space, and then map the result back to the original parameters. This turns a diagonal posterior in the rotated basis into a structured covariance in parameter space. We will go into why diagonal uncertainty is too limited, how SOAP provides a useful learned basis, and how EVON combines that basis with practical variational updates. This results in a method that stays close to modern training pipelines while capturing parameter correlations that diagonal methods miss. We will also see how EVON recovers meaningful covariance structure in logistic regression and improves language model pretraining and posterior sampling compared to IVON.
Bio: Adrian Robert Minut is a PhD student at Sapienza University of Rome, co-advised by Prof. Emanuele Rodolà and Prof. Iacopo Masi. His research focuses on Large Language Models (LLMs), specifically exploring model merging and uncertainty estimation. His primary goal is to develop methods that make these models more robust, efficient, and transparent.
Yohan Jung & Emtiyaz Khan: Compact Memory (15 min)
Christopher J. Anders: Data-Similarity and Data-Influence for Understanding LLMs (15 min)
Hiro Ishii: Federated Learning (15 min)
Kenichi Bannai: Understanding and Describing Principles behind Bayes Duality (30 min)
Bio: Kenichi Bannai is a Team Director at RIKEN AIP, and a Professor of Mathematics and Keio University. His speciality has been and is arithmetic geometry, a branch in pure mathematics.
Julyan Arbel: From Priors to Pruning: recent developments in Bayesian neural networks (30 min)
Abstract: In this talk I will describe results of the French Stat Theory team in the Bayes-Duality project, focusing on Bayesian neural networks. I will present work on the statistical properties of Bayesian neural network priors, and discuss uncertainty quantification in Bayesian deep learning through tempered posteriors. Finally, I will introduce a new framework based on sources of uncertainty, which enables adaptive posterior concentration and naturally leads to sparse, self-pruning Bayesian neural networks with compact architectures. I will highlight both theoretical guarantees and empirical results.
Bio: Julyan Arbel is a researcher at Inria Grenoble, France, working on Bayesian nonparametrics, Bayesian deep learning, variational inference, and simulation-based inference. He serves as Associate Editor for journals including Bayesian Analysis and Statistics and Computing, and as Area Chair for major machine learning conferences. He is an active member of ISBA, where he currently serves as Chair-Elect of the BayesAI Section and Social Media Officer.
Abstract: Foundation models like GPT-4 have dramatically altered the modern work landscape for many industries reliant on language tasks, but no equivalent model exists yet for scientific applications. Incorporating foundation models into research workflows could enable unprecedented discoveries that connect traditionally distinct scientific sub-disciplines. However, mainstream foundation models trained on human-scale datasets will be insufficient for analyzing most scientific phenomena -- a foundation model for science will require special consideration for the requirements of scientific datasets, especially those with wide dynamic ranges. In this talk, I will introduce the Polymathic AI initiative: our goal is to accelerate the development of versatile foundation models tailored for numerical datasets and scientific machine learning tasks. The challenge we are undertaking is to build AI models which leverage information from heterogeneous datasets and across different scientific fields, which, contrary to domains like natural language processing, do not share a unifying representation (i.e., text). Such models can then be used as strong baselines or be further fine-tuned by scientists for specific applications. This approach has the potential to democratize AI in science by providing off-the-shelf models that have stronger priors (i.e., background knowledge) for shared general concepts such as causality, measurement, signal processing, and even more specialized shared concepts like wave-like behavior, which otherwise would need to be learned from scratch. I will present our initial papers and projects, including large scientific datasets designed for large scale training "MultiModal Universe" and "The Well".
Bio: Dr. Shirley Ho is a Professor of Physics and Data Science at New York University, Group Leader of Cosmology and Machine Learning at Simons Foundation with visiting appointments at Princeton University and Carnegie Mellon University. She is also co-Founder and Director of Polymathic AI, a research collective aiming at advancing science through multi-disciplinary AI. Dr. Shirley Ho is noted for her work in leading the early adoption of Artificial Intelligence in Astrophysics. In particular, her team at Carnegie Mellon University was the first to apply 3D convolutional neural network in astrophysics, the same team then accelerated astrophysical simulations with deep learning for the first time. Her current team at Simons Foundation, NYU and Princeton is the first to combine symbolic regression and neural network to recover physical laws from observations directly. Her team also led the first development and deployment of deep learning accelerated simulation based inference framework for large astronomical surveys. Her team further accelerated physical simulations ranging from fluid dynamics simulations to planetary dynamics simulations using modern deep learning techniques, and developed techniques in interpretable machine learning for science. Dr. Ho has won several prizes for her significant contributions to the fields of astrophysics and AI. The list includes Schmidt Sciences AI2050 Senior Fellow, National Blavatnik Award Finalist, European Physical Society Giuseppe and Vanna Cocconi Prize in cosmology, NASA Group Achievement Award, Macronix Prize, Carnegie Science Award. She was also elected as a Fellow of the International Astrostatistics Association in 2020. She served on advisory boards at NASA, DOE, National Academies and numerous NSF institutes. She always tries to balance between Machine learning, the Universe, and life, and almost always fails to do so.
Morning Session (chair: Julyan Arbel)
Abstract: Modern AI research often pays a high tax for early commitments: once we train, fine-tune, quantize, or deploy a model, changing course becomes expensive. This talk argues for treating model spaces as objects to be navigated, rather than searched blindly. I will discuss three instruments for reducing this tax: inspection, to read trained networks as dynamical systems; inversion, to ask what hidden states still remember; and steering, to reuse expensive robustness improvements as transferable directions. The common theme is extracting more signal from each trained model, turning checkpoints into maps, witnesses, and directions for future decisions.
Bio: Emanuele Rodolà is a Professor of Computer Science at Sapienza University of Rome, where he leads the GLADIA group on AI. His work in this field has been supported by an ERC grant, a FIS grant, and a Google Research Award among others. In the past, he was a postdoctoral researcher at USI Lugano (2016–2017), a Humboldt Fellow at TU Munich (2013–2016), and a JSPS Fellow at the University of Tokyo (2013), in addition to visiting periods at Tel Aviv University, Technion, École Polytechnique, and Stanford. He is a fellow of ELLIS and a fellow of the Young Academy of Europe. Professor Rodolà has received numerous awards for his research and plays an active role in the academic community, serving on program committees and as Area Chair for major conferences in AI and ML. His current research focuses primarily on neural model fusion, representation learning, language models, ML for audio, and multimodal learning, with around 200 publications in these areas. His work has been featured in media outlets including Fortune, Wired, RAI, and Internazionale.
Abstract: Can we learn more from data than existed in the generating process itself? Can new and useful information be constructed from merely applying deterministic transformations to existing data? Can the learnable content in data be evaluated without considering a downstream task? On these questions, Shannon information and Kolmogorov complexity come up nearly empty-handed, in part because they assume observers with unlimited computational capacity and fail to target the useful information content. In this talk we identify and exemplify three seeming paradoxes in information theory: (1) information cannot be increased by deterministic transformations; (2) information is independent of the order of data; (3) likelihood modeling is merely distribution matching. To shed light on the tension between these results and modern practice, and to quantify the value of data, we introduce epiplexity, a formalization of information capturing what computationally bounded observers can learn from data. Epiplexity captures the structural content in data while excluding time-bounded entropy, the random unpredictable content exemplified by pseudorandom number generators and chaotic dynamical systems. With these concepts, we demonstrate how information can be created with computation, how it depends on the ordering of the data, and how likelihood modeling can produce more complex programs than present in the data generating process itself. We also present practical procedures to estimate epiplexity which we show capture differences across data sources, track with downstream performance, and highlight dataset interventions that improve out-of-distribution generalization. In contrast to principles of model selection, epiplexity provides a theoretical foundation for data selection, guiding how to select, generate, or transform data for learning systems.
Bio: Andrew Gordon Wilson is a Professor at the Courant Institute of Mathematical Sciences and Center for Data Science at New York University, and an Amazon Scholar. He aims to develop a prescriptive foundation for intelligent systems. His work includes generalization theory, Bayesian inference, equivariances, time-series forecasting, and scientific applications, particularly in computational biology, physics, and materials. He has received the NSF Career Award, the Heilbronn Distinguished Fellowship, the Amazon Research Award, and several best paper, dissertation, reviewer, and area chair awards.
Afternoon Session (chair: Florence Forbes)
Abstract: Bayesian inference admits a variational form: the posterior minimizes expected loss regularized by the KL divergence to the prior. Recent generalizations vary the loss, divergence, and variational family independently, which can yield inconsistent objectives (e.g., a Gaussian family against a bounded-support prior results in infinite KL divergence). We instead couple these ingredients through a single Fenchel-Young term built from a convex regularizer, ruling out inconsistent combinations. Choosing a Tsallis negentropy as the regularizer, posteriors become deformed exponential families with adaptive support or heavy tails, recovering standard Bayes at the Shannon limit. Conjugacy and additive canonical updates are preserved, yielding generalized versions of EM, VAE, and Bayesian-learning-rule algorithms.
Bio: Mário Figueiredo is an IST Distinguished Professor and holder of the Feedzai Chair on Machine Learning at Instituto Superior Técnico (IST), University of Lisbon. He also serves as a group leader at Instituto de Telecomunicações and is the Director of the ELLIS Unit Lisbon. His research career spans a broad range of topics, including statistical machine learning, signal processing, optimization, and inverse problems. He is a Fellow of IEEE, IAPR, EURASIP, and ELLIS, and member of the Lisbon Academy of Sciences and the Portuguese Academy of Engineering.
Abstract: Importance weighted variational inference (VI) approximates densities known up to a normalizing constant by optimizing bounds that tighten with the number of Monte Carlo samples N. Standard optimization relies on reparameterized gradient estimators, which are well-studied theoretically yet restrict both the choice of the data-generating process and the variational approximation. While REINFORCE gradient estimators do not suffer from such restrictions, they lack rigorous theoretical justification. In this paper, we provide the first comprehensive analysis of REINFORCE gradient estimators in importance weighted VI, leveraging this theoretical foundation to diagnose and resolve fundamental deficiencies in current state-of-the-art estimators. Specifically, we introduce and examine a generalized family of variational inference for Monte Carlo objectives (VIMCO) gradient estimators. We prove that state-of-the-art VIMCO gradient estimators exhibit a vanishing signal-to-noise ratio (SNR) as N increases, which prevents effective optimization. To overcome this issue, we propose the novel VIMCO-⋆ gradient estimator and show that it averts the SNR collapse of existing VIMCO gradient estimators by achieving a √N SNR scaling instead. We demonstrate its superior empirical performance compared to current VIMCO implementations in challenging settings where reparameterized gradients are typically unavailable.
Bio: Kamélia Daudel is an Assistant Professor of Statistics at ESSEC Business School. Prior to that, she was a postdoctoral researcher in the Department of Statistics at the University of Oxford working with Arnaud Doucet. Her research lies in the field of Bayesian Inference. In particular, she is interested in Variational Inference methods which go beyond the commonly-used parametric variational distribution framework and which involve flexible variational bounds.