arXiv AI

SVRG and Beyond via Posterior Correction

arXiv:2512. 01930v2 Announce Type: replace-cross Abstract: Stochastic Variance Reduced Gradient (SVRG) and its variants aim to speed-up training by using gradient corrections.

arXiv Machine Learning
Aug 27

Fast rates in Bayesian online learning with approximate posteriors

The paper investigates how fast predictive regret guarantees of exact Bayesian online learning can be maintained when using approximate posterior methods. It establishes a general theorem linking the cumulative cost of posterior approximation to the contraction radius of the exact Gibbs posterior and the Wasserstein distance between approximate and exact posteriors. Three concrete online learning scenarios—linear models, infinite‑dimensional exponential families, and Gaussian process regression—illustrate that appropriately accurate approximations (projected Langevin, truncation, and sparse variational posteriors) preserve fast regret bounds while reducing computational demands.

By Ilsang Ohn
arXiv Machine Learning
Oct 16

Learn Only Where You Can't Compute: Structured Corrections to Gaussian Process Posteriors

The paper introduces a structured posterior‑correction framework that blends a tractable Gaussian reference with data‑driven corrections learned via diffusion models. After applying mean correction and covariance calibration, the diffusion model focuses on a low‑dimensional subspace that captures discrepancies from the Gaussian reference, while the remaining space stays Gaussian. Experiments on three scientific inference tasks show that these corrections recover hidden modes, improve sample structure, and reduce prediction error compared to the Gaussian reference, with trade‑offs between accuracy and computational cost relative to full‑field generative models.

By Tobias Weber, Carla Sagebiel, Philipp Hennig
arXiv Machine Learning
Aug 28

A Flexible Empirical Bayes Approach to Generalized Linear Models, with Applications to Sparse Logistic Regression

The paper presents a tuning‑free empirical Bayes framework for Bayesian generalized linear models that uses a novel mean‑field variational inference algorithm. By estimating the prior within the VI procedure and optimizing the posterior mean directly, the method reduces optimization complexity and supports scalable solvers like L‑BFGS and stochastic gradient descent. Applied to sparse logistic regression, the approach shows superior predictive performance compared to existing methods.

By Dongyue Xie, Matthew Stephens
arXiv Machine Learning
Aug 18

Adaptive Optimization via Momentum on Variance-Normalized Gradients

arXiv:2602. 10204v2 Announce Type: replace Abstract: We introduce MVN-Grad (Momentum on Variance-Normalized Gradients), an Adam-style optimizer that improves stability and performance by combining two complementary ideas: variance-based normalization and momentum applied after normalization.

By Francisco Patitucci, Aryan Mokhtari
arXiv Machine Learning
Oct 23

The Fenchel-Young Generalization of Bayesian Principles

The paper extends the classical conjugate Bayesian framework by leveraging the Fenchel‑Young inequality to define a generalized evidence lower bound that transcends the usual KL geometry. This leads to a new notion of conjugacy—closure of prior‑potential families that remain affine under loss translation—allowing additive canonical updates, parameter‑dependent support, and tunable heavy‑tailed posteriors. The authors also derive a Fenchel‑Young generalization of EM, encompassing both classical and hard EM, and demonstrate its utility in generalized Bayesian linear regression and sparse Gaussian mixture models.

By Sophia Sklaviadis, Thomas Moellenhoff, Emtiyaz Khan, Andre Martins, Mario Figueiredo
arXiv Machine Learning
6d ago

Conservative neural posterior estimation via distributionally robust training

The paper introduces DRO-NPE, a distributionally robust neural posterior estimation method that replaces the standard NPE objective with a worst‑case loss over a Wasserstein ambiguity set. It presents KL‑based metrics for miscoverage and miscalibration, demonstrating that the DRO‑NPE objective mitigates overfitting and reduces posterior overconfidence. Experiments on benchmark simulation‑based inference tasks show that DRO‑NPE consistently improves coverage and calibration while narrowing the gap between empirical and population NPE loss, especially in low‑simulation regimes.

By William Laplante, Yuga Hikida, Charita Dellaporta, Fran\c{c}ois-Xavier Briol, Ayush Bharti
arXiv Machine Learning
Oct 23

The Bayesian Learning Rule Beyond KL Geometry

The paper investigates how the Bayesian Learning Rule (BLR), traditionally tied to Kullback‑Leibler divergence, can be extended to other geometries. It demonstrates that additive BLR updates are possible using mixed‑space Bregman or Fenchel‑Young discrepancies, leading to generalized maximum‑entropy families and new canonical gradient updates. For example, applying the Tsallis negentropy with quadratic statistics yields bounded‑support, heavy‑tailed q‑Gaussian posteriors and a simple Newton‑like implementation, with experiments on CIFAR‑100 showing controllable support and tail behavior and competitive performance.

By Sophia Sklaviadis, Wu Lin, Andre Martins, Mario Figueiredo, Thomas Moellenhoff, Emtiyaz Khan