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Carl Henrik Ek

20 accepted papers

2025

Efficient Model-Based Reinforcement Learning Through Optimistic Thompson Sampling

ICLR 2025poster

Learning complex robot behavior through interactions with the environment necessitates principled exploration. Effective strategies should prioritize exploring regions of the state-action space that maximize rewards, with optimistic exploration emerging as a promising direction aligned with this ide…

Cited by 0SourcePDFScholar
2025

Linear combinations of latents in generative models: subspaces and beyond

ICLR 2025poster

Sampling from generative models has become a crucial tool for applications like data synthesis and augmentation. Diffusion, Flow Matching and Continuous Normalising Flows have shown effectiveness across various modalities, and rely on latent variables for generation. For experimental design or creat…

2025

No-Regret Thompson Sampling for Finite-Horizon Markov Decision Processes with Gaussian Processes

NeurIPS 2025poster

Thompson sampling (TS) is a powerful and widely used strategy for sequential decision-making, with applications ranging from Bayesian optimization to reinforcement learning (RL). Despite its success, the theoretical foundations of TS remain limited, particularly in settings with complex temporal str…

Cited by 0SourceScholar
2025

VIKING: Deep variational inference with stochastic projections

NeurIPS 2025poster

Variational mean field approximations tend to struggle with contemporary overparametrized deep neural networks. Where a Bayesian treatment is usually associated with high-quality predictions and uncertainties, the practical reality has been the opposite, with unstable training, poor predictive power…

Cited by 0SourceScholar
2024

Reparameterization invariance in approximate Bayesian inference

NeurIPS 2024spotlight

Current approximate posteriors in Bayesian neural networks (BNNs) exhibit a crucial limitation: they fail to maintain invariance under reparameterization, i.e. BNNs assign different posterior densities to different parametrizations of identical functions. This creates a fundamental flaw in the appli…

Cited by 4SourcePDFScholar
2023

Mode-constrained Model-based Reinforcement Learning via Gaussian Processes

AISTATS 2023poster

Model-based reinforcement learning (RL) algorithms do not typically consider environments with multiple dynamic modes, where it is beneficial to avoid inoperable or undesirable modes. We present a model-based RL algorithm that constrains training to a single dynamic mode with high probability. This…

2022

Aligned Multi-Task Gaussian Process

AISTATS 2022poster

Multi-task learning requires accurate identification of the correlations between tasks. In real-world time-series, tasks are rarely perfectly temporally aligned; traditional multi-task models do not account for this and subsequent errors in correlation estimation will result in poor predictive perfo…

2021

Black-box density function estimation using recursive partitioning

ICML 2021spotlight

We present a novel approach to Bayesian inference and general Bayesian computation that is defined through a sequential decision loop. Our method defines a recursive partitioning of the sample space. It neither relies on gradients nor requires any problem-specific tuning, and is asymptotically exact…

2021

Deep Neural Networks as Point Estimates for Deep Gaussian Processes

NeurIPS 2021poster

Neural networks and Gaussian processes are complementary in their strengths and weaknesses. Having a better understanding of their relationship comes with the promise to make each method benefit from the strengths of the other. In this work, we establish an equivalence between the forward passes of…

Cited by 46SourcePDFScholar
2021

Trajectory Optimisation in Learned Multimodal Dynamical Systems via Latent-ODE Collocation

ICRA 2021poster

This paper presents a two-stage method to perform trajectory optimisation in multimodal dynamical systems with unknown nonlinear stochastic transition dynamics. The method finds trajectories that remain in a preferred dynamics mode where possible and in regions of the transition dynamics model that…

Cited by 12SourceScholar
2020

Compositional uncertainty in deep Gaussian processes

UAI 2020poster

Gaussian processes (GPs) are nonparametric priors over functions. Fitting a GP implies computing a posterior distribution of functions consistent with the observed data. Similarly, deep Gaussian processes (DGPs) should allow us to compute a posterior distribution of compositions of multiple function…

Cited by 24SourcePDFScholar
2020

Modulating Surrogates for Bayesian Optimization

ICML 2020poster

Bayesian optimization (BO) methods often rely on the assumption that the objective function is well-behaved, but in practice, this is seldom true for real-world objectives even if noise-free observations can be collected. Common approaches, which try to model the objective as precisely as possible,…

2019

DP-GP-LVM: A Bayesian Non-Parametric Model for Learning Multivariate Dependency Structures

ICML 2019oral

We present a non-parametric Bayesian latent variable model capable of learning dependency structures across dimensions in a multivariate setting. Our approach is based on flexible Gaussian process priors for the generative mappings and interchangeable Dirichlet process priors to learn the structure.…

Cited by 5SourcePDFScholar
2018

Bayesian Alignments of Warped Multi-Output Gaussian Processes

NeurIPS 2018poster

We propose a novel Bayesian approach to modelling nonlinear alignments of time series based on latent shared information. We apply the method to the real-world problem of finding common structure in the sensor data of wind turbines introduced by the underlying latent and turbulent wind field. The pr…

Cited by 24SourcePDFScholar
2016

Active exploration using Gaussian Random Fields and Gaussian Process Implicit Surfaces

IROS 2016poster

In this work we study the problem of exploring surfaces and building compact 3D representations of the environment surrounding a robot through active perception. We propose an online probabilistic framework that merges visual and tactile measurements using Gaussian Random Field and Gaussian Process…

Cited by 43SourceScholar
2016

Probabilistic consolidation of grasp experience

ICRA 2016poster

We present a probabilistic model for joint representation of several sensory modalities and action parameters in a robotic grasping scenario. Our non-linear probabilistic latent variable model encodes relationships between grasp-related parameters, learns the importance of features, and expresses co…

Cited by 13SourceScholar
2015

Learning Predictive State Representation for in-hand manipulation

ICRA 2015poster

We study the use of Predictive State Representation (PSR) for modeling of an in-hand manipulation task through interaction with the environment. We extend the original PSR model to a new domain of in-hand manipulation and address the problem of partial observability by introducing new kernel-based f…

Cited by 16SourceScholar