An optimal first-order method for smooth and strongly convex composite optimization and its stationary limit
Abstract
We introduce Prox-ITEM, an optimal proximal-gradient method for minimizing f + g, where f is smooth and strongly convex, and g is convex, proper, and lower semicontinuous. In the smooth case g = 0, Prox-ITEM reduces to the information-theoretic exact method (ITEM). We prove an exact distance-to-solution bound for Prox-ITEM with the same distance-convergence rate as ITEM, and show that this rate is minimax optimal among span-based first-order methods using the same number of gradient-oracle calls for f and an arbitrary number of proximal-oracle calls for g. We also identify the stationary limit of Prox-ITEM, denoted Prox-TMM, which gives a proximal extension of the triple momentum method (TMM) to the composite setting and achieves the corresponding TMM distance-convergence rate.
Related
- Near-Optimal Single-Loop Predictor--Corrector Extragradient Method for Strongly Convex--Strongly Concave Minimax Optimization
- An Optimal First-Order Active-Hull Method for Convex Composite Hölder Smooth Optimization
- Near-Optimal Complexity of Finite-Sum Nonconvex-Strongly-Concave Minimax Optimization
- Accelerated Proximal Gradient Method for Non-Strongly Convex Time-Varying Optimization
- Near-Optimal Exact-Value Zeroth-Order Complexity for Smooth Strongly Convex Optimization
BibTeX
@misc{upadhyaya2026optimal,
title = {{An optimal first-order method for smooth and strongly convex composite optimization and its stationary limit}},
author = {Manu Upadhyaya and Daniel Berg Thomsen and Aymeric Dieuleveut and Adrien B Taylor},
howpublished = {HAL},
year = {2026},
month = aug,
url = {https://hal.science/hal-05858407v1},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - An optimal first-order method for smooth and strongly convex composite optimization and its stationary limit
AU - Manu Upadhyaya
AU - Daniel Berg Thomsen
AU - Aymeric Dieuleveut
AU - Adrien B Taylor
PY - 2026
DA - 2026/08/21
PB - HAL
UR - https://hal.science/hal-05858407v1
AB - We introduce Prox-ITEM, an optimal proximal-gradient method for minimizing f + g, where f is smooth and strongly convex, and g is convex, proper, and lower semicontinuous. In the smooth case g = 0, Prox-ITEM reduces to the information-theoretic exact method (ITEM). We prove an exact distance-to-solution bound for Prox-ITEM with the same distance-convergence rate as ITEM, and show that this rate is minimax optimal among span-based first-order methods using the same number of gradient-oracle calls for f and an arbitrary number of proximal-oracle calls for g. We also identify the stationary limit of Prox-ITEM, denoted Prox-TMM, which gives a proximal extension of the triple momentum method (TMM) to the composite setting and achieves the corresponding TMM distance-convergence rate.
ER -