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.
Replace the usual parameter-plus-momentum Langevin state with a three-level chain consisting of parameters, velocity, and acceleration, while injecting Gaussian noise only into the highest auxiliary state. At a saddle, the escaping direction has a positive rate given by a cubic characteristic equation; use this rate to choose damping or adapt the temperature so that basin escape is accelerated without making the dynamics unstable.
Replace Langevin or random-walk sampling for a strongly log-concave neural subproblem with randomized Hamiltonian trajectories. Each iteration draws a fresh Gaussian velocity, integrates position and velocity for a random triangular or exponential duration, and discards the terminal velocity before the next refresh. The target is a regularized posterior over a convex neural-network head, where the paper's accelerated dependence on the strong-convexity parameter is applicable.