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Fred Roosta

21 accepted papers

2026

Counterfactual Explanations on Robust Perceptual Geodesics

ICLR 2026poster

Latent-space optimization methods for counterfactual explanations—framed as minimal semantic perturbations that change model predictions—inherit the ambiguity of Wachter et al.’s objective: the choice of distance metric dictates whether perturbations are meaningful or adversarial. Existing approache…

Cited by 0SourceScholar
2026

Is the Last Layer Sufficient for Uncertainty Quantification?

ICML 2026poster

Epistemic uncertainty quantification (UQ) for deep neural networks (DNNs) is a requirement for safe adoption of AI in mission-critical settings. Several leading methods for UQ linearize DNNs to form Bayesian Generalized Linear Models (GLMs), where epistemic uncertainty is modeled via the predictive …

Cited by 0SourceScholar
2025

Determinant Estimation under Memory Constraints and Neural Scaling Laws

ICML 2025poster

Calculating or accurately estimating log-determinants of large positive semi-definite matrices is of fundamental importance in many machine learning tasks. While its cubic computational complexity can already be prohibitive, in modern applications even storing the matrices themselves can pose a memo…

2025

Latent Refinement via Flow Matching for Training-free Linear Inverse Problem Solving

NeurIPS 2025poster

Recent advances in *inverse problem* solving have increasingly adopted flow *priors* over diffusion models due to their ability to construct straight probability paths from noise to data, thereby enhancing efficiency in both training and inference. However, current flow-based inverse solvers face tw…

Cited by 0SourceScholar
2025

Uncertainty Quantification with the Empirical Neural Tangent Kernel

NeurIPS 2025poster

While neural networks have demonstrated impressive performance across various tasks, accurately quantifying uncertainty in their predictions is essential to ensure their trustworthiness and enable widespread adoption in critical systems. Several Bayesian uncertainty quantification (UQ) methods exist…

Cited by 0SourceScholar
2024

Manifold Integrated Gradients: Riemannian Geometry for Feature Attribution

ICML 2024poster

In this paper, we dive into the reliability concerns of Integrated Gradients (IG), a prevalent feature attribution method for black-box deep learning models. We particularly address two predominant challenges associated with IG: the generation of noisy feature visualizations for vision models and th…

2023

Monotonicity and Double Descent in Uncertainty Estimation with Gaussian Processes

ICML 2023poster

Despite their importance for assessing reliability of predictions, uncertainty quantification (UQ) measures in machine learning models have only recently begun to be rigorously characterized. One prominent issue is the *curse of dimensionality*: it is commonly believed that the marginal likelihood s…

Cited by 7SourcePDFScholar
2021

Avoiding Kernel Fixed Points: Computing with ELU and GELU Infinite Networks

AAAI 2021technical

Analysing and computing with Gaussian processes arising from infinitely wide neural networks has recently seen a resurgence in popularity. Despite this, many explicit covariance functions of networks with activation functions used in modern networks remain unknown. Furthermore, while the kernels of…

2021

Non-PSD matrix sketching with applications to regression and optimization

UAI 2021poster

A variety of dimensionality reduction techniques have been applied for computations involving large matrices. The underlying matrix is randomly compressed into a smaller one, while approximately retaining many of its original properties. As a result, much of the expensive computation can be performe…

Cited by 2SourcePDFScholar
2021

Shadow Manifold Hamiltonian Monte Carlo

AISTATS 2021poster

Hamiltonian Monte Carlo and its descendants have found success in machine learning and computational statistics due to their ability to draw samples in high dimensions with greater efficiency than classical MCMC. One of these derivatives, Riemannian manifold Hamiltonian Monte Carlo (RMHMC), better a…

2021

Stochastic continuous normalizing flows: training SDEs as ODEs

UAI 2021poster

We provide a general theoretical framework for stochastic continuous normalizing flows, an extension of continuous normalizing flows for density estimation of stochastic differential equations (SDEs). Using the theory of rough paths, the underlying Brownian motion is treated as a latent variable and…

Cited by 13SourcePDFScholar
2018

FLAG n’ FLARE: Fast Linearly-Coupled Adaptive Gradient Methods

AISTATS 2018poster

We consider first order gradient methods for effectively optimizing a composite objective in the form of a sum of smooth and, potentially, non-smooth functions. We present accelerated and adaptive gradient methods, called FLAG and FLARE, which can offer the best of both worlds. They can achieve the…

Cited by 0SourcePDFScholar
2018

GIANT: Globally Improved Approximate Newton Method for Distributed Optimization

NeurIPS 2018poster

For distributed computing environment, we consider the empirical risk minimization problem and propose a distributed and communication-efficient Newton-type optimization method. At every iteration, each worker locally finds an Approximate NewTon (ANT) direction, which is sent to the main driver. The…

Cited by 169SourcePDFScholar
2018

Out-of-sample extension of graph adjacency spectral embedding

ICML 2018oral

Many popular dimensionality reduction procedures have out-of-sample extensions, which allow a practitioner to apply a learned embedding to observations not seen in the initial training sample. In this work, we consider the problem of obtaining an out-of-sample extension for the adjacency spectral em…

Cited by 22SourcePDFScholar
2017

Union of Intersections (UoI) for Interpretable Data Driven Discovery and Prediction

NeurIPS 2017poster

The increasing size and complexity of scientific data could dramatically enhance discovery and prediction for basic scientific applications, e.g., neuroscience, genetics, systems biology, etc. Realizing this potential, however, requires novel statistical analysis methods that are both interpretable…

Cited by 26SourcePDFScholar
2016

Sub-sampled Newton Methods with Non-uniform Sampling

NeurIPS 2016poster

We consider the problem of finding the minimizer of a convex function $F: \mathbb R^d \rightarrow \mathbb R$ of the form $F(w) \defeq \sum_{i=1}^n f_i(w) + R(w)$ where a low-rank factorization of $\nabla^2 f_i(w)$ is readily available.We consider the regime where $n \gg d$. We propose randomized New…

Cited by 151SourcePDFScholar