2026/07/30 by Jianfeng Lu, Yinchen Luo
Mathematics · Computer Science · #math.NA #cs.LG #cs.NA #math.PR #math.ST #stat.TH #msc:65C05 #msc:60J25 #msc:65C40 #msc:65Y20
arxiv created 2026/07/30 · arxiv updated 2026/07/31
Let μ(d x)∝ e-U(x) d x on \Rd, where U is m-strongly convex and L-smooth, and denote by κ=L/m the condition number. We consider windowed thinning, an exact simulation method for the bouncy particle sampler and the coordinate Zigzag process. The method divides a trajectory into deterministic windows and uses a gradient evaluation at the beginning of each window to construct a tractable local envelope for the event rate. Combining this construction with quantitative mixing estimates and finite-time bounds on the expected numbers of bounces and flips yields query complexity guarantees from a Gaussian cold start. For total-variation error ε, the expected query counts are O(κ1/2d (dlogκ+log\frac1ε)) gradient queries for the bouncy particle sampler and O(κd1/4(dlogκ+log\frac1ε)) full-gradient equivalents for Zigzag, where d coordinate-partial queries count as one equivalent.