ML: Sampling

Machine-learning ideas tagged Sampling in the ML taxonomy of the Math2NN corpus.

✗ Mechanism failed 2026

ESS-Controlled Autoregressive CTMC Sampler

Generate discrete configurations globally with an autoregressive model and then refine them using a continuous-time Markov chain of local single-site replacement moves. Use importance weights and the paper's normalized ESS to adapt the CTMC refinement budget and to reject training batches in which the proposal has collapsed onto a few modes.

Useful7/10
Difficulty6/10
Novelty7/10
Paper: FrOGS: Discrete Neural Sampler for Independent Alloy Configurations Across Chemical Conditions arXiv:2609.02948
△ Mechanism confirmed, baseline not beaten 2026

CVaR-tail active residual correction

Train a cheap neural surrogate globally, then use an ensemble or bootstrap covariance to identify inputs near the estimated upper-tail boundary and inputs where high-fidelity correction is uncertain. Fit a Tikhonov-regularized residual model on the acquired expensive labels and use the corrected predictor for CVaR estimation or risk-constrained optimization. The acquisition policy deliberately ignores easy central-region samples unless they influence the tail threshold.

Useful7/10
Difficulty5/10
Novelty6/10
Paper: Risk-averse design optimization with CVaR constraints via multifidelity tail-region correction arXiv:2608.29222
Unverified 2026

Best-of-N Certification Width

Attach an exact structural uncertainty report to any best-of-N evaluation: after measuring reliability only for budgets n = 1,...,m, report that deployment reliability at budget N is unresolved by at least B_{m,N}. Use this width to select the smallest audit budget that makes a claimed reliability gap meaningful, or reject model comparisons whose validation budget lies below the square-root-of-N threshold.

Useful6/10
Difficulty3/10
Novelty8/10
Paper: The geometry of AI validation: Exact certification limits for iid best-of-N search arXiv:2608.21496
Unverified 2026

Certified partition-function reranking

Replace MAP scoring of discrete latent configurations by comparison of the total energy-model mass assigned to each candidate class. Estimate each class partition function with annealed importance sampling driven by identical random seeds, then return a prediction only when a paired bootstrap confidence interval certifies that its log-partition score exceeds every competitor.

Useful5/10
Difficulty6/10
Novelty6/10
Paper: Certified decoding of quantum LDPC codes arXiv:2608.25545