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James Thornton

12 accepted papers

2025

Composition and Control with Distilled Energy Diffusion Models and Sequential Monte Carlo

AISTATS 2025poster

Diffusion models may be formulated as a time-indexed sequence of energy-based models, where the score corresponds to the negative gradient of an energy function. As opposed to learning the score directly, an energy parameterization is attractive as the energy itself can be used to control generation…

Cited by 25SourceScholar
2025

Mechanisms of Projective Composition of Diffusion Models

ICML 2025poster

We study the theoretical foundations of composition in diffusion models, with a particular focus on out-of-distribution extrapolation and length-generalization. Prior work has shown that composing distributions via linear score combination can achieve promising results, including length-generalizati…

Cited by 15SourcePDFScholar
2025

Shielded Diffusion: Generating Novel and Diverse Images using Sparse Repellency

ICML 2025poster

The adoption of text-to-image diffusion models raises concerns over reliability, drawing scrutiny under the lens of various metrics like calibration, fairness, or compute efficiency. We focus in this work on two issues that arise when deploying these models: a lack of diversity when prompting images…

Cited by 0SourcePDFScholar
2025

Simple ReFlow: Improved Techniques for Fast Flow Models

ICLR 2025poster

Diffusion and flow-matching models achieve remarkable generative performance but at the cost of many neural function evaluations (NFE), which slows inference and limits applicability to time-critical tasks. The ReFlow procedure can accelerate sampling by straightening generation trajectories. But it…

Cited by 5SourcePDFScholar
2025

Target Concrete Score Matching: A Holistic Framework for Discrete Diffusion

ICML 2025poster

Discrete diffusion is a promising framework for modeling and generating discrete data. In this work, we present Target Concrete Score Matching (TCSM), a novel and versatile objective for training and fine-tuning discrete diffusion models. TCSM provides a general framework with broad applicability. I…

Cited by 1SourcePDFScholar
2024

Careful with that Scalpel: Improving Gradient Surgery with an EMA

ICML 2024poster

Beyond minimizing a single training loss, many deep learning estimation pipelines rely on an auxiliary objective to quantify and encourage desirable properties of the model (e.g. performance on another dataset, robustness, agreement with a prior). Although the simplest approach to incorporating an a…

Cited by 0SourcePDFScholar
2024

Contrasting Multiple Representations with the Multi-Marginal Matching Gap

ICML 2024oral

Learning meaningful representations of complex objects that can be seen through multiple ($k\geq 3$) views or modalities is a core task in machine learning. Existing methods use losses originally intended for paired views, and extend them to $k$ views, either by instantiating $\tfrac12k(k-1)$ loss-p…

Cited by 4SourcePDFScholar
2024

Progressive Entropic Optimal Transport Solvers

NeurIPS 2024poster

Optimal transport (OT) has profoundly impacted machine learning by providing theoretical and computational tools to realign datasets. In this context, given two large point clouds of sizes $n$ and $m$ in $\mathbb{R}^d$, entropic OT (EOT) solvers have emerged as the most reliable tool to either solve…

Cited by 4SourcePDFScholar
2022

Riemannian Score-Based Generative Modelling

NeurIPS 2022accept

Score-based generative models (SGMs) are a powerful class of generative models that exhibit remarkable empirical performance. Score-based generative modelling (SGM) consists of a ``noising'' stage, whereby a diffusion is used to gradually add Gaussian noise to data, and a generative model, which ent…

2021

Differentiable Particle Filtering via Entropy-Regularized Optimal Transport

ICML 2021oral

Particle Filtering (PF) methods are an established class of procedures for performing inference in non-linear state-space models. Resampling is a key ingredient of PF necessary to obtain low variance likelihood and states estimates. However, traditional resampling methods result in PF-based loss fun…

2021

Diffusion Schrödinger Bridge with Applications to Score-Based Generative Modeling

NeurIPS 2021spotlight

Progressively applying Gaussian noise transforms complex data distributions to approximately Gaussian. Reversing this dynamic defines a generative model. When the forward noising process is given by a Stochastic Differential Equation (SDE), Song et al (2021) demonstrate how the time inhomogeneous dr…