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Related papers: Riemannian Optimistic Algorithms

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Riemannian convex optimization and minimax optimization have recently drawn considerable attention. Their appeal lies in their capacity to adeptly manage the non-convexity of the objective function as well as constraints inherent in the…

Optimization and Control · Mathematics 2024-06-04 Zihao Hu , Guanghui Wang , Xi Wang , Andre Wibisono , Jacob Abernethy , Molei Tao

Existing approaches to online convex optimization (OCO) make sequential one-slot-ahead decisions, which lead to (possibly adversarial) losses that drive subsequent decision iterates. Their performance is evaluated by the so-called regret…

Systems and Control · Computer Science 2017-11-22 Tianyi Chen , Qing Ling , Georgios B. Giannakis

Smooth minimax optimization problems play a central role in a wide range of applications, including machine learning, game theory, and operations research. However, existing algorithmic frameworks vary significantly depending on the problem…

Optimization and Control · Mathematics 2025-06-10 Taoli Zheng , Anthony Man-Cho So , Jiajin Li

Recent research has shown that quasar-convexity can be found in applications such as identification of linear dynamical systems and generalized linear models. Such observations have in turn spurred exciting developments in design and…

Optimization and Control · Mathematics 2024-07-08 Yuen-Man Pun , Iman Shames

To deal with changing environments, a new performance measure -- adaptive regret, defined as the maximum static regret over any interval, was proposed in online learning. Under the setting of online convex optimization, several algorithms…

Machine Learning · Computer Science 2021-05-17 Lijun Zhang , Guanghui Wang , Wei-Wei Tu , Zhi-Hua Zhou

This work considers optimization of composition of functions in a nested form over Riemannian manifolds where each function contains an expectation. This type of problems is gaining popularity in applications such as policy evaluation in…

Optimization and Control · Mathematics 2024-03-20 Dewei Zhang , Sam Davanloo Tajbakhsh

Consider an online convex optimization problem where the loss functions are self-concordant barriers, smooth relative to a convex function $h$, and possibly non-Lipschitz. We analyze the regret of online mirror descent with $h$. Then, based…

Machine Learning · Statistics 2023-09-22 Chung-En Tsai , Hao-Chung Cheng , Yen-Huan Li

In two-player zero-sum games, the learning dynamic based on optimistic Hedge achieves one of the best-known regret upper bounds among strongly-uncoupled learning dynamics. With an appropriately chosen learning rate, the social and…

Machine Learning · Computer Science 2025-10-14 Taira Tsuchiya

We investigate online convex optimization in non-stationary environments and choose dynamic regret as the performance measure, defined as the difference between cumulative loss incurred by the online algorithm and that of any feasible…

Machine Learning · Computer Science 2024-04-09 Peng Zhao , Yu-Jie Zhang , Lijun Zhang , Zhi-Hua Zhou

The online optimization problem with non-convex loss functions over a closed convex set, coupled with a set of inequality (possibly non-convex) constraints is a challenging online learning problem. A proximal method of multipliers with…

Optimization and Control · Mathematics 2022-04-26 Liwei Zhang , Haoyang Liu , Xiantao Xiao

Greedy algorithms have been successfully analyzed and applied in training neural networks for solving variational problems, ensuring guaranteed convergence orders. In this paper, we extend the analysis of the orthogonal greedy algorithm…

Numerical Analysis · Mathematics 2025-04-21 Jinchao Xu , Xiaofeng Xu

This paper considers distributed online optimization with time-varying coupled inequality constraints. The global objective function is composed of local convex cost and regularization functions and the coupled constraint function is the…

Optimization and Control · Mathematics 2019-06-06 Xinlei Yi , Xiuxian Li , Lihua Xie , Karl H. Johansson

We provide an online convex optimization algorithm with regret that interpolates between the regret of an algorithm using an optimal preconditioning matrix and one using a diagonal preconditioning matrix. Our regret bound is never worse…

Machine Learning · Computer Science 2019-05-31 Ashok Cutkosky , Tamas Sarlos

Stochastic and adversarial data are two widely studied settings in online learning. But many optimization tasks are neither i.i.d. nor fully adversarial, which makes it of fundamental interest to get a better theoretical understanding of…

Machine Learning · Computer Science 2025-11-03 Sarah Sachs , Hedi Hadiji , Tim van Erven , Cristobal Guzman

Some of the most compelling applications of online convex optimization, including online prediction and classification, are unconstrained: the natural feasible set is R^n. Existing algorithms fail to achieve sub-linear regret in this…

Machine Learning · Computer Science 2012-11-13 Matthew Streeter , H. Brendan McMahan

We study a variant of online convex optimization where the player is permitted to switch decisions at most $S$ times in expectation throughout $T$ rounds. Similar problems have been addressed in prior work for the discrete decision set…

Machine Learning · Computer Science 2023-09-19 Uri Sherman , Tomer Koren

Despite remarkable empirical success, the training dynamics of generative adversarial networks (GAN), which involves solving a minimax game using stochastic gradients, is still poorly understood. In this work, we analyze last-iterate…

Machine Learning · Computer Science 2020-10-13 Ernest K. Ryu , Kun Yuan , Wotao Yin

Optimization with orthogonality constraints frequently arises in various fields such as machine learning. Riemannian optimization offers a powerful framework for solving these problems by equipping the constraint set with a Riemannian…

Optimization and Control · Mathematics 2025-05-20 Andi Han , Pierre-Louis Poirion , Akiko Takeda

We study the iteration complexity of the optimistic gradient descent-ascent (OGDA) method and the extra-gradient (EG) method for finding a saddle point of a convex-concave unconstrained min-max problem. To do so, we first show that both…

Optimization and Control · Mathematics 2020-09-30 Aryan Mokhtari , Asuman Ozdaglar , Sarath Pattathil

Regret minimization is treated as the golden rule in the traditional study of online learning. However, regret minimization algorithms tend to converge to the static optimum, thus being suboptimal for changing environments. To address this…

Machine Learning · Computer Science 2020-02-07 Lijun Zhang , Shiyin Lu , Tianbao Yang