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Ruben Ohana

16 accepted papers

2026

Overtone: Cyclic Patch Modulation for Cleaner, Faster Physics Emulators

ICLR 2026poster

Transformer-based PDE surrogates achieve remarkable performance but face two key challenges: fixed patch sizes cause systematic error accumulation at harmonic frequencies, and computational costs remain inflexible regardless of problem complexity or available resources. We introduce Overtone, a unif…

Cited by 0SourcecodeScholar
2026

Walrus: A Cross-domain Foundation Model for Continuum Dynamics

ICML 2026spotlight

Foundation models have transformed machine learning for language and vision, but achieving comparable impact in physical simulation remains a challenge. Data heterogeneity and unstable long-term dynamics inhibit learning from sufficiently diverse dynamics, while varying resolutions and dimensionalit…

Cited by 0SourceScholar
2025

AION-1: Omnimodal Foundation Model for Astronomical Sciences

NeurIPS 2025poster

While foundation models have shown promise across a variety of fields, astronomy lacks a unified framework for joint modeling across its highly diverse data modalities. In this paper, we present AION-1, the first large-scale multimodal foundation family of models for astronomy. AION-1 enables arbitr…

Cited by 0SourceScholar
2025

Lost in Latent Space: An Empirical Study of Latent Diffusion Models for Physics Emulation

NeurIPS 2025poster

The steep computational cost of diffusion models at inference hinders their use as fast physics emulators. In the context of image and video generation, this computational drawback has been addressed by generating in the latent space of an autoencoder instead of the pixel space. In this work, we inv…

Cited by 0SourcecodeScholar
2025

Predicting partially observable dynamical systems via diffusion models with a multiscale inference scheme

NeurIPS 2025poster

Conditional diffusion models provide a natural framework for probabilistic prediction of dynamical systems and have been successfully applied to fluid dynamics and weather prediction. However, in many settings, the available information at a given time represents only a small fraction of what is nee…

Cited by 0SourceScholar
2024

Listening to the noise: Blind Denoising with Gibbs Diffusion

ICML 2024poster

In recent years, denoising problems have become intertwined with the development of deep generative models. In particular, diffusion models are trained like denoisers, and the distribution they model coincide with denoising priors in the Bayesian picture. However, denoising through diffusion-based p…

2024

MoMo: Momentum Models for Adaptive Learning Rates

ICML 2024poster

Training a modern machine learning architecture on a new task requires extensive learning-rate tuning, which comes at a high computational cost. Here we develop new Polyak-type adaptive learning rates that can be used on top of any momentum method, and require less tuning to perform well. We first d…

2024

Multiple Physics Pretraining for Spatiotemporal Surrogate Models

NeurIPS 2024poster

We introduce multiple physics pretraining (MPP), an autoregressive task-agnostic pretraining approach for physical surrogate modeling of spatiotemporal systems with transformers. In MPP, rather than training one model on a specific physical system, we train a backbone model to predict the dynamics o…

Cited by 3SourcePDFScholar
2024

The Well: a Large-Scale Collection of Diverse Physics Simulations for Machine Learning

NeurIPS 2024poster

Machine learning based surrogate models offer researchers powerful tools for accelerating simulation-based workflows. However, as standard datasets in this space often cover small classes of physical behavior, it can be difficult to evaluate the efficacy of new approaches. To address this gap, we in…

2023

Complex-to-Real Sketches for Tensor Products with Applications to the Polynomial Kernel

AISTATS 2023poster

Randomized sketches of a tensor product of $p$ vectors follow a tradeoff between statistical efficiency and computational acceleration. Commonly used approaches avoid computing the high-dimensional tensor product explicitly, resulting in a suboptimal dependence of $O(3^p)$ in the embedding dimension…

2023

Shedding a PAC-Bayesian Light on Adaptive Sliced-Wasserstein Distances

ICML 2023poster

The Sliced-Wasserstein distance (SW) is a computationally efficient and theoretically grounded alternative to the Wasserstein distance. Yet, the literature on its statistical properties -- or, more accurately, its generalization properties -- with respect to the distribution of slices, beyond the un…

2022

Adversarial Robustness by Design Through Analog Computing And Synthetic Gradients

ICASSP 2022accepted

We propose a new defense mechanism against adversarial at-tacks inspired by an optical co-processor, providing robustness without compromising natural accuracy in both white-box and black-box settings. This hardware co-processor performs a nonlinear fixed random transformation, where the parameters…

Cited by 0SourceScholar
2021

Align, then memorise: the dynamics of learning with feedback alignment

ICML 2021spotlight

Direct Feedback Alignment (DFA) is emerging as an efficient and biologically plausible alternative to backpropagation for training deep neural networks. Despite relying on random feedback weights for the backward pass, DFA successfully trains state-of-the-art models such as Transformers. On the othe…

2021

Photonic Differential Privacy with Direct Feedback Alignment

NeurIPS 2021poster

Optical Processing Units (OPUs) -- low-power photonic chips dedicated to large scale random projections -- have been used in previous work to train deep neural networks using Direct Feedback Alignment (DFA), an effective alternative to backpropagation. Here, we demonstrate how to leverage the intrin…

Cited by 13SourcePDFScholar
2020

Kernel Computations from Large-Scale Random Features Obtained by Optical Processing Units

ICASSP 2020accepted

Approximating kernel functions with random features (RFs) has been a successful application of random projections for nonparametric estimation. However, performing random projections presents computational challenges for large-scale problems. Recently, a new optical hardware called Optical Processin…

Cited by 0SourceScholar
2020

Reservoir Computing meets Recurrent Kernels and Structured Transforms

NeurIPS 2020oral

Reservoir Computing is a class of simple yet efficient Recurrent Neural Networks where internal weights are fixed at random and only a linear output layer is trained. In the large size limit, such random neural networks have a deep connection with kernel methods. Our contributions are threefold: a)…