arXiv Machine Learning
Sep 10

Sharp Structure-Agnostic Minimax Risk for Partial Linear Models

arXiv:2609. 07997v1 Announce Type: new Abstract: We characterize the sharp structure-agnostic minimax risk for coefficient estimation in the partial linear model when the outcome and treatment nuisances are learned by two distinct black-box learners, which resolves the open problem in double machine learning posed by Gu (2025).

By Haichen Hu, David Simchi-Levi
arXiv Machine Learning
Aug 28

Adversarial Training Without Input Gradients via Low-Rank Householder Expansions

The paper introduces a method for adversarial training that avoids computing input gradients by using a low‑rank Householder expansion (LRHE) to directly generate small‑norm adversarial examples from a network’s parameters. This approach requires only forward passes and standard back‑propagation, eliminating the inner maximization loop and reducing computational cost to roughly 2.8 PGD steps per epoch. The resulting models achieve comparable robustness to multi‑step PGD training for small relative ε budgets, demonstrating the feasibility of gradient‑free adversarial training.

By Tiana C. Johnson, Donsub Rim