A simple universal algorithm for high-dimensional integration
Takashi Goda, David Krieg
TL;DR
The paper tackles efficient high-dimensional integration over $[0,1]^d$ for functions in weighted Korobov spaces $\mathcal{H}_{d,\alpha,\gamma}$ by proposing a simple universal randomized lattice-quadrature algorithm. It randomizes over primes $p$ and generating vectors $z$, and uses the median of independent lattice estimates to achieve near-optimal convergence: the randomized error satisfies $e^{\rm ran}_{d,\alpha,\gamma} \le C\,n^{-\alpha-1/2+\varepsilon}$ and the deterministic error satisfies $e^{\rm det}_{d,\alpha,\gamma} \le C\,n^{-\alpha+\varepsilon}$ (with high probability). The analysis leverages the Korobov kernel, the Fourier-weight sum $V_d(\alpha,\gamma)$, and a median-amplification technique, showing dimension-free guarantees when $\gamma \in \ell_{1/\alpha}$, and extends to nonperiodic functions via tent- or smooth-transforms. Numerical experiments with periodic and nonperiodic test functions corroborate the theoretical rates, demonstrating universality and robustness across smoothness levels and dimensions. The result is a simple, implementable, and near-universal approach for high-dimensional quadrature that adaptively attains near-optimal rates without detailed prior knowledge of the integrand.
Abstract
We present a simple universal algorithm for high-dimensional integration which has the optimal error rate (independent of the dimension) in all weighted Korobov classes both in the randomized and the deterministic setting. Our theoretical findings are complemented by numerical tests.
