Progressive Power Homotopy for Non-convex Optimization

Fuente: arXiv
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Autore principale: Xu, Chen
Natura: Preprint
Pubblicazione: 2026
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author Xu, Chen
author_facet Xu, Chen
contents We propose a novel first-order method for non-convex optimization of the form $\max_{\bm{w}\in\mathbb{R}^d}\mathbb{E}_{\bm{x}\sim\mathcal{D}}[f_{\bm{w}}(\bm{x})]$, termed Progressive Power Homotopy (Prog-PowerHP). The method applies stochastic gradient ascent to a surrogate objective obtained by first performing a power transformation and then Gaussian smoothing, $F_{N,σ}(\bmμ):=\mathbb{E}_{\bm{w}\sim\mathcal{N}(\bmμ,σ^2I_d),\bm{x}\sim\mathcal{D}}[e^{Nf_w(\bm{x})}]$, while progressively increasing the power parameter $N$ and decreasing the smoothing scale $σ$ along the optimization trajectory. We prove that, under mild regularity conditions, Prog-PowerHP converges to a small neighborhood of the global optimum with an iteration complexity scaling nearly as $O(d^2\varepsilon^{-2})$. Empirically, Prog-PowerHP demonstrates clear advantages in phase retrieval when the samples-to-dimension ratio approaches the information-theoretic limit, and in training two-layer neural networks in under-parameterized regimes. These results suggest that Prog-PowerHP is particularly effective for navigating cluttered non-convex landscapes where standard first-order methods struggle.
format Preprint
id arxiv_https___arxiv_org_abs_2601_15915
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Progressive Power Homotopy for Non-convex Optimization
Xu, Chen
Optimization and Control
Artificial Intelligence
Machine Learning
65K05, 68T07, 90C30, 68W40
We propose a novel first-order method for non-convex optimization of the form $\max_{\bm{w}\in\mathbb{R}^d}\mathbb{E}_{\bm{x}\sim\mathcal{D}}[f_{\bm{w}}(\bm{x})]$, termed Progressive Power Homotopy (Prog-PowerHP). The method applies stochastic gradient ascent to a surrogate objective obtained by first performing a power transformation and then Gaussian smoothing, $F_{N,σ}(\bmμ):=\mathbb{E}_{\bm{w}\sim\mathcal{N}(\bmμ,σ^2I_d),\bm{x}\sim\mathcal{D}}[e^{Nf_w(\bm{x})}]$, while progressively increasing the power parameter $N$ and decreasing the smoothing scale $σ$ along the optimization trajectory. We prove that, under mild regularity conditions, Prog-PowerHP converges to a small neighborhood of the global optimum with an iteration complexity scaling nearly as $O(d^2\varepsilon^{-2})$. Empirically, Prog-PowerHP demonstrates clear advantages in phase retrieval when the samples-to-dimension ratio approaches the information-theoretic limit, and in training two-layer neural networks in under-parameterized regimes. These results suggest that Prog-PowerHP is particularly effective for navigating cluttered non-convex landscapes where standard first-order methods struggle.
title Progressive Power Homotopy for Non-convex Optimization
topic Optimization and Control
Artificial Intelligence
Machine Learning
65K05, 68T07, 90C30, 68W40
url https://arxiv.org/abs/2601.15915