Provable Acceleration for Diffusion Models under Minimal Assumptions
- URL: http://arxiv.org/abs/2410.23285v2
- Date: Sun, 03 Nov 2024 14:56:22 GMT
- Title: Provable Acceleration for Diffusion Models under Minimal Assumptions
- Authors: Gen Li, Changxiao Cai,
- Abstract summary: We propose a novel training-free acceleration scheme for score-based samplers.
Under minimal assumptions, our scheme achieves $varepsilon$-accuracy in total variation within $widetildeO(d5/4/sqrtvarepsilon)$ iterations.
- Score: 8.15094483029656
- License:
- Abstract: While score-based diffusion models have achieved exceptional sampling quality, their sampling speeds are often limited by the high computational burden of score function evaluations. Despite the recent remarkable empirical advances in speeding up the score-based samplers, theoretical understanding of acceleration techniques remains largely limited. To bridge this gap, we propose a novel training-free acceleration scheme for stochastic samplers. Under minimal assumptions -- namely, $L^2$-accurate score estimates and a finite second-moment condition on the target distribution -- our accelerated sampler provably achieves $\varepsilon$-accuracy in total variation within $\widetilde{O}(d^{5/4}/\sqrt{\varepsilon})$ iterations, thereby significantly improving upon the $\widetilde{O}(d/\varepsilon)$ iteration complexity of standard score-based samplers. Notably, our convergence theory does not rely on restrictive assumptions on the target distribution or higher-order score estimation guarantees.
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