arXiv Machine Learning

Learning CNF Formulas from Uniform Random Solutions: Near-Tight Sample Complexity for Valiant's Algorithm

arXiv Machine Learning
Sep 25

Bandit Multiclass PAC Learning: Corrected Lower Bounds, Exact Families, and a Confidence Direct-Sum Phenomenon

The paper revisits realizable multiclass PAC learning with bandit feedback, correcting a previously claimed lower bound on sample complexity. It introduces a new anchored dimension, “aBDS,” and establishes a constant‑free three‑part lower bound, while also providing tighter upper bounds that eliminate dependence on the total label count. The authors demonstrate that the optimal sample complexity can vary dramatically even among classes with identical dimensional profiles, revealing a confidence direct‑sum phenomenon and a rank‑saturation phase transition.

By Guangjian Zhang
arXiv Machine Learning
Sep 10

Smoothed Picard Hamiltonian Monte Carlo

arXiv:2609.06906v1 Announce Type: cross Abstract: We develop a new low-accuracy sampler, called \emph{smoothed Picard Hamiltonian Monte Carlo}, which combines Gaussian smoothing, Picard iteration, an...

By Fan Chen, Sinho Chewi, Jianfeng Lu, Matthew S Zhang
arXiv Machine Learning
Jun 18

How fast can you find a good hypothesis?

arXiv:2509. 03734v3 Announce Type: replace-cross Abstract: In the hypothesis selection problem, we are given sample and query access to finite set of candidate distributions (hypotheses), $\mathcal{H} = \{H_1, \ldots, H_n\}$, and samples from an unknown distribution $P$, both over a domain $\mathcal{X}$.

By Anders Aamand, Maryam Aliakbarpour, Justin Y. Chen, Sandeep Silwal
arXiv Machine Learning
Oct 12

Learning by Compression: Risk Estimates Attain the Law-of-Large-Numbers Rate

The paper shows that for learning algorithms based on preferential compression, the risk can be bounded by the compression complexity term λk/N plus an O(1/√N) term, eliminating the previously assumed logarithmic factor. This bound holds uniformly over all possible values of λk and matches the law‑of‑large‑numbers rate of empirical risk estimation. The authors also demonstrate that the leading λk/N term is necessary and analyze when empirical risk converges at O(1/√N) versus slower or inconsistent rates, while the complexity‑based estimator retains the O(1/√N) rate.

By Simone Garatti, Marco C. Campi