The existing method of GS-PowerOpt solves the non-convex optimization problem of the form
maxx∈Rdf(x) through maximizing a Gaussian-smoothed surrogate
FN,σ(μ)=Ex∼N(μ,σ2Id)[eNf(x)]. We analyze the role of the smoothing radius
σ>0 and identify a limitation of the fixed-
σ design used in GS-PowerOpt. Specifically,
σ induces an inherent exploration--refinement tradeoff: a larger
σ improves global exploration and finite-time surrogate optimization, but may distort the location of the surrogate maximizer; in contrast, a smaller
σ better preserves local structure but can weaken gradient signals away from high-value regions. To address this limitation, we propose GS-PowerHP, a power-smoothed homotopy method with an incrementally decaying
σ schedule. The proposed mechanism uses larger smoothing radii in early iterations to maintain informative gradient signals when the iterate is far from high-value regions, and gradually decreases
σ to improve local refinement near the maximizer. We provide theoretical results showing that this decaying schedule improves the exploration--refinement tradeoff of fixed-
σ power smoothing. Empirically, GS-PowerHP consistently outperforms the fixed-
σ baseline and exhibits robust performance across different optimization tasks, including adversarial attacks on ImageNet (
d=150,528), where it substantially improves over other smoothing-based zeroth-order methods.