arXiv Machine Learning

The Sharp Tail of Uniform Stability

Hugging Face Trending Papers
Aug 25

The Sharp Tail of Uniform Stability

Uniform stability controls how much one training example can change the loss at any test point. A new logarithmic-free upper bound shows that a $γ$-uniformly stable algorithm with loss in $[0,L]$ has...

arXiv Machine Learning
Aug 12

Optimistic Rates for Multiclass PAC Learning

arXiv:2608. 10869v1 Announce Type: new Abstract: Worst-case multiclass bounds do not become smaller when the best classifier is already nearly correct: what is missing is an optimistic rate, a guarantee whose fluctuation scales with the oracle risk itself.

By Xiaoyu Li, Andi Han, Jiaojiao Jiang, Junbin Gao
Hugging Face Trending Papers
Aug 5

The Sample Complexity of Distributionally Robust PAC Learning under Cressie--Read Divergences

We study distributionally robust PAC learning for the $0$--$1$-loss, where adversarial perturbations of the data distribution are constrained by a Cressie--Read divergence of order $k>1$ and radius $ρ\geq 0$. For hypothesis classes with VC dimension $d$, we establish realizable and agnostic sample-complexity bounds tight up to constant and logarithmic factors, respectively; ordinary empirical risk minimization attains both rates up to logarithmic factors.

arXiv Machine Learning
2d ago

Restricted Eigenvalues Beyond Gaussian Width: Threshold Occupancy under Heavy Tails

The paper investigates restricted eigenvalue (RE) bounds for norm‑regularized estimators under heavy‑tailed designs. It shows that the previously conjectured sample‑size law based on Gaussian width fails for heavy‑tailed measurements, due to a phenomenon called simultaneous threshold occupancy. The authors provide explicit counterexamples, derive worst‑case sample‑complexity bounds, and compare the behavior of heavy‑tailed versus Gaussian designs on constant‑width polyhedral descent cones.

By Shi Fu, Huibo Xu, Qixin Zhang, Dacheng Tao
arXiv Machine Learning
Aug 11

Optimal Learning Under Tsybakov Noise

arXiv:2608. 08416v1 Announce Type: new Abstract: Probably Approximately Correct (PAC) learning [Val84] is a fundamental learning model that has been extensively investigated.

By Steve Hanneke, Hongao Wang, Mingyue Xu