# Bandit Convex Optimization in Non-stationary Environments

arXiv: https://arxiv.org/abs/1907.12340 · HTML: https://mlsanity.com/paper/1907.12340/

## Key facts

- Cited by 41 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 29 Jul 2019.

## Built on by (most cited first, 30 of 41)

- [Adaptivity and Non-stationarity: Problem-dependent Dynamic Regret for Online Convex Optimization](https://mlsanity.com/paper/2112.14368/) (2021)
- [A Simple Approach for Non-stationary Linear Bandits](https://mlsanity.com/paper/2103.05324/) (2021)
- [Open-environment Machine Learning](https://mlsanity.com/paper/2206.00423/) (2022)
- [Non-stationary Online Learning with Memory and Non-stochastic Control](https://mlsanity.com/paper/2102.03758/) (2021)
- [Adapting to Online Label Shift with Provable Guarantees](https://mlsanity.com/paper/2207.02121/) (2022)
- [Corralling a Larger Band of Bandits: A Case Study on Switching Regret for Linear Bandits](https://mlsanity.com/paper/2202.06151/) (2022)
- [Adapting to Continuous Covariate Shift via Online Density Ratio Estimation](https://mlsanity.com/paper/2302.02552/) (2023)
- [Efficient Methods for Non-stationary Online Learning](https://mlsanity.com/paper/2309.08911/) (2023)
- [Dynamic Regret of Online Markov Decision Processes](https://mlsanity.com/paper/2208.12483/) (2022)
- [From Linear to Linearizable Optimization: A Novel Framework with Applications to Stationary and Non-stationary DR-submodular Optimization](https://mlsanity.com/paper/2405.00065/) (2024)
- [Meta-Learning Adversarial Bandit Algorithms](https://mlsanity.com/paper/2307.02295/) (2023)
- [Online Convex Optimization with Unbounded Memory](https://mlsanity.com/paper/2210.09903/) (2022)
- [Efficient Utility-Preserving Machine Unlearning with Implicit Gradient Surgery](https://mlsanity.com/paper/2510.22124/) (2025)
- [Improved Dimension Dependence for Bandit Convex Optimization with Gradient Variations](https://mlsanity.com/paper/2602.04761/) (2026)
- [On Dynamic Regret and Constraint Violations in Constrained Online Convex Optimization](https://mlsanity.com/paper/2301.09808/) (2023)
- [A Unified Framework for Analyzing Meta-algorithms in Online Convex Optimization](https://mlsanity.com/paper/2402.08621/) (2024)
- [Dynamic Regret via Discounted-to-Dynamic Reduction with Applications to Curved Losses and Adam Optimizer](https://mlsanity.com/paper/2602.08372/) (2026)
- [Non-stationary Delayed Online Convex Optimization: From Full-information to Bandit Setting](https://mlsanity.com/paper/2305.12131/) (2023)
- [Online Convex Optimization with Switching Cost and Delayed Gradients](https://mlsanity.com/paper/2310.11880/) (2023)
- [Non-Stationary Lipschitz Bandits](https://mlsanity.com/paper/2505.18871/) (2025)
- [Parameter-free Algorithms for the Stochastically Extended Adversarial Model](https://mlsanity.com/paper/2510.04685/) (2025)
- [Upper-Linearizability of Online Non-Monotone DR-Submodular Maximization over Down-Closed Convex Sets](https://mlsanity.com/paper/2602.20578/) (2026)
- [Non-Parametric Stochastic Sequential Assignment With Random Arrival Times](https://mlsanity.com/paper/2106.04944/) (2021)
- [Distributed Consensus Algorithm for Decision-Making in Multi-agent Multi-armed Bandit](https://mlsanity.com/paper/2306.05998/) (2023)
- [Risk-averse Learning with Non-Stationary Distributions](https://mlsanity.com/paper/2404.02988/) (2024)
- [Partially Performative Prediction](https://mlsanity.com/paper/2606.07890/) (2026)
- [Online Convex Optimization with Dueling Feedback](https://mlsanity.com/paper/2608.15050/) (2026)
- [Online Ad Procurement in Non-stationary Autobidding Worlds](https://mlsanity.com/paper/2307.05698/) (2023)
- [Adaptive Regret for Bandits Made Possible: Two Queries Suffice](https://mlsanity.com/paper/2401.09278/) (2024)
- [Distributed Management of Fluctuating Energy Resources in Dynamic Networked Systems](https://mlsanity.com/paper/2405.19015/) (2024)

## Abstract (arXiv)

Bandit Convex Optimization (BCO) is a fundamental framework for modeling sequential decision-making with partial information, where the only feedback available to the player is the one-point or two-point function values. In this paper, we investigate BCO in non-stationary environments and choose the dynamic regret as the performance measure, which is defined as the difference between the cumulative loss incurred by the algorithm and that of any feasible comparator sequence. Let T be the time horizon and PT be the path-length of the comparator sequence that reflects the non-stationarity of environments. We propose a novel algorithm that achieves O(T3/4(1+PT)1/2) and O(T1/2(1+PT)1/2) dynamic regret respectively for the one-point and two-point feedback models. The latter result is optimal, matching the Omega(T1/2(1+PT)1/2) lower bound established in this paper. Notably, our algorithm is more adaptive to non-stationary environments since it does not require prior knowledge of the path-length PT ahead of time, which is generally unknown.
