Improved Gradient Descent Lower Bounds Beyond Nesterov
Abstract
We study how far gradient descent (GD) can be accelerated by predetermined stepsizes in smooth convex optimization. Going beyond the classical Ω(n−2) first-order oracle lower bound of Nemirovsky and Yudin (1983), we prove an Ω(n−1.6342) non-anytime lower bound and an Ω(n−1.2408) anytime lower bound. These improve the recent Ω(n−1.932) non-anytime lower bound of Ma and Chen (2026) and the Ω(n−4/3) anytime lower bound of Tsai et al. (2026), respectively. Both results continue to hold when the stepsizes may be negative. Our anytime lower bound also shows that the O(n−log2(1+√2)) rate of non-anytime silver schedules (Altschuler and Parrilo, 2025; Grimmer et al., 2025) is unattainable in the anytime setting. This establishes a strict separation between the two settings.
Related
- Convergence Analysis of Nesterov's Accelerated Gradient Descent under Relaxed Assumptions
- Stronger Lower Bounds for (Non-)Anytime Acceleration of Gradient Descent
- Lower Bounds on Inference Complexity for Polyak-Ruppert Averaged Stochastic Gradient Descent
- Improved Convergence Rates for Stochastic Multi-Gradient Descent which Close the Gap: A Proof by AI
- On the Nonoccurrence of Gradient Restart in Nesterov Accelerated Gradient Method
BibTeX
@misc{ye2026improved,
title = {{Improved Gradient Descent Lower Bounds Beyond Nesterov}},
author = {Yuhan Ye and Kaizhao Liu},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.02855},
eprint = {2609.02855},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.02855},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Improved Gradient Descent Lower Bounds Beyond Nesterov
AU - Yuhan Ye
AU - Kaizhao Liu
PY - 2026
DA - 2026/09/03
PB - arXiv
DO - 10.48550/arxiv.2609.02855
UR - https://arxiv.org/abs/2609.02855
AB - We study how far gradient descent (GD) can be accelerated by predetermined stepsizes in smooth convex optimization. Going beyond the classical Ω(n^−2) first-order oracle lower bound of Nemirovsky and Yudin (1983), we prove an Ω(n^−1.6342) non-anytime lower bound and an Ω(n^−1.2408) anytime lower bound. These improve the recent Ω(n^−1.932) non-anytime lower bound of Ma and Chen (2026) and the Ω(n^−4/3) anytime lower bound of Tsai et al. (2026), respectively. Both results continue to hold when the stepsizes may be negative. Our anytime lower bound also shows that the O(n^−log_2(1+√2)) rate of non-anytime silver schedules (Altschuler and Parrilo, 2025; Grimmer et al., 2025) is unattainable in the anytime setting. This establishes a strict separation between the two settings.
ER -