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Ullrich Koethe

11 accepted papers

2025

Learning Distances from Data with Normalizing Flows and Score Matching

ICML 2025poster

Density-based distances (DBDs) provide a principled approach to metric learning by defining distances in terms of the underlying data distribution. By employing a Riemannian metric that increases in regions of low probability density, shortest paths naturally follow the data manifold. Fermat distanc…

Cited by 2SourcePDFScholar
2025

TRADE: Transfer of Distributions between External Conditions with Normalizing Flows

AISTATS 2025poster

Modeling distributions that depend on external control parameters is a common scenario in diverse applications like molecular simulations, where system properties like temperature affect molecular configurations. Despite the relevance of these applications, existing solutions are unsatisfactory as t…

Cited by 0SourcecodeScholar
2024

Consistency Models for Scalable and Fast Simulation-Based Inference

NeurIPS 2024poster

Simulation-based inference (SBI) is constantly in search of more expressive and efficient algorithms to accurately infer the parameters of complex simulation models. In line with this goal, we present consistency models for posterior estimation (CMPE), a new conditional sampler for SBI that inherits…

2024

Learning Distributions on Manifolds with Free-Form Flows

NeurIPS 2024poster

We propose Manifold Free-Form Flows (M-FFF), a simple new generative model for data on manifolds. The existing approaches to learning a distribution on arbitrary manifolds are expensive at inference time, since sampling requires solving a differential equation. Our method overcomes this limitation b…

2024

Leveraging Self-Consistency for Data-Efficient Amortized Bayesian Inference

ICML 2024poster

We propose a method to improve the efficiency and accuracy of amortized Bayesian inference by leveraging universal symmetries in the joint probabilistic model of parameters and data. In a nutshell, we invert Bayes' theorem and estimate the marginal likelihood based on approximate representations of…

2024

Lifting Architectural Constraints of Injective Flows

ICLR 2024poster

Normalizing Flows explicitly maximize a full-dimensional likelihood on the training data. However, real data is typically only supported on a lower-dimensional manifold leading the model to expend significant compute on modeling noise. Injective Flows fix this by jointly learning a manifold and the…

Cited by 11SourcePDFScholar
2024

On the Universality of Volume-Preserving and Coupling-Based Normalizing Flows

ICML 2024poster

We present a novel theoretical framework for understanding the expressive power of normalizing flows. Despite their prevalence in scientific applications, a comprehensive understanding of flows remains elusive due to their restricted architectures. Existing theorems fall short as they require the us…

Cited by 5SourcePDFScholar
2023

On the Convergence Rate of Gaussianization with Random Rotations

ICML 2023poster

Gaussianization is a simple generative model that can be trained without backpropagation. It has shown compelling performance on low dimensional data. As the dimension increases, however, it has been observed that the convergence speed slows down. We show analytically that the number of required lay…

2022

Whitening Convergence Rate of Coupling-based Normalizing Flows

NeurIPS 2022accept

Coupling-based normalizing flows (e.g. RealNVP) are a popular family of normalizing flow architectures that work surprisingly well in practice. This calls for theoretical understanding. Existing work shows that such flows weakly converge to arbitrary data distributions. However, they make no stateme…

Cited by 10SourcePDFScholar