Saved in:
Bibliographic Details
Main Authors: Gong, Xuchen, Li, Tian
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2510.16157
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909854269964288
author Gong, Xuchen
Li, Tian
author_facet Gong, Xuchen
Li, Tian
contents Classic zeroth-order optimization approaches typically optimize for a smoothed version of the original function, i.e., the expected objective under randomly perturbed model parameters. This can be interpreted as encouraging the loss values in the perturbation set to be small on average. Popular sharpness-aware minimization (SAM) objectives, however, typically focus on the largest loss within the neighborhood to arrive at flat minima more effectively. In this work, we connect zeroth-order optimization (and its corresponding objectives) with SAM approaches explicitly, through an exponential tilting objective that provides a smooth transition between the average- and the max-loss formulations. We explore new zeroth-order algorithms to solve a soft SAM objective parameterized by a tilting parameter $t$. We provide precise characterizations of the sharpness notions of the tilted SAM framework. Practically, our approach can be used as a gradient-free and memory-efficient alternative to SAM variants, and it achieves better generalization compared to vanilla zeroth-order baselines on a wide range of downstream tasks, including classification, multiple choice QA, and language generation.
format Preprint
id arxiv_https___arxiv_org_abs_2510_16157
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Zeroth-Order Sharpness-Aware Learning with Exponential Tilting
Gong, Xuchen
Li, Tian
Machine Learning
Computation and Language
Classic zeroth-order optimization approaches typically optimize for a smoothed version of the original function, i.e., the expected objective under randomly perturbed model parameters. This can be interpreted as encouraging the loss values in the perturbation set to be small on average. Popular sharpness-aware minimization (SAM) objectives, however, typically focus on the largest loss within the neighborhood to arrive at flat minima more effectively. In this work, we connect zeroth-order optimization (and its corresponding objectives) with SAM approaches explicitly, through an exponential tilting objective that provides a smooth transition between the average- and the max-loss formulations. We explore new zeroth-order algorithms to solve a soft SAM objective parameterized by a tilting parameter $t$. We provide precise characterizations of the sharpness notions of the tilted SAM framework. Practically, our approach can be used as a gradient-free and memory-efficient alternative to SAM variants, and it achieves better generalization compared to vanilla zeroth-order baselines on a wide range of downstream tasks, including classification, multiple choice QA, and language generation.
title Zeroth-Order Sharpness-Aware Learning with Exponential Tilting
topic Machine Learning
Computation and Language
url https://arxiv.org/abs/2510.16157