Optimization & Variational Methods

MSC 49-90

Convex and non-convex optimization, combinatorial optimization, variational analysis, optimal control.

42 problems

UnsolvedMajor

Optimal Mixing Time for Log-Concave Sampling

Mathematical StatisticsProbability TheoryOptimization & Variational Methods
UnsolvedMajor

KLS Conjecture (Kannan–Lovász–Simonovits)

Probability TheoryOptimization & Variational MethodsAnalysis & PDEs

Posed by Ravi Kannan, László Lovász, Miklós Simonovits (1995)

UnsolvedMajor

Multiple Risk Control Beyond Sequential Order: Graph-Structured Dependencies

Mathematical StatisticsLearning TheoryOptimization & Variational Methods

Posed by Joshi, Sun, Hassani, and Dobriban (2025)

UnsolvedNotable

Smoothed Complexity of the Simplex Method

Optimization & Variational MethodsTheoretical Computer Science

Posed by Spielman & Teng (implicit) (2004)

UnsolvedNotable

Minimax Rate for Wasserstein Distance Estimation in High Dimensions

Mathematical StatisticsProbability TheoryOptimization & Variational Methods
Unsolved

Does the score-matched optimal convex estimator attain the full semiparametric efficiency bound?

Mathematical StatisticsLearning TheoryOptimization & Variational Methods

Sourced from the work of Oliver Y. Feng, Yu-Chun Kao, Min Xu, Richard J. Samworth

Unsolved

Quantify and characterize the efficiency gap induced by convex-loss restriction for non-log-concave errors

Mathematical StatisticsLearning TheoryOptimization & Variational Methods

Sourced from the work of Oliver Y. Feng, Yu-Chun Kao, Min Xu, Richard J. Samworth

Unsolved

Optimal Break-Point Estimation Rate in Grouped Time-Varying Network VAR

Mathematical StatisticsOptimization & Variational MethodsInformation Theory

Sourced from the work of Degui Li, Bin Peng, Songqiao Tang, Wei Biao Wu

Unsolved

Full Multiple-Break Theory for Latent Group Structure and Coefficients

Mathematical StatisticsOptimization & Variational MethodsInformation Theory

Sourced from the work of Degui Li, Bin Peng, Songqiao Tang, Wei Biao Wu

Unsolved

Asymptotic Normality of Spectrum-Aware Debiasing Beyond Right-Rotationally Invariant Designs

Mathematical StatisticsOptimization & Variational MethodsInformation Theory

Sourced from the work of Yufan Li, Pragya Sur

Unsolved

Theory for Debiased PCR Under General Covariate Models

Mathematical StatisticsOptimization & Variational MethodsInformation Theory

Sourced from the work of Yufan Li, Pragya Sur

Unsolved

Overparameterized optimal subsample size for infinite-ensemble subagging

Mathematical StatisticsOptimization & Variational MethodsInformation Theory

Sourced from the work of Takuya Koriyama, Pratik Patil, Jin-Hong Du, Kai Tan, Pierre C. Bellec

Unsolved

Nonasymptotic guarantees for bagged regularized M-estimators

Mathematical StatisticsOptimization & Variational MethodsInformation Theory

Sourced from the work of Takuya Koriyama, Pratik Patil, Jin-Hong Du, Kai Tan, Pierre C. Bellec

Unsolved

Extension beyond convex differentiable-loss framework

Mathematical StatisticsOptimization & Variational MethodsInformation Theory

Sourced from the work of Takuya Koriyama, Pratik Patil, Jin-Hong Du, Kai Tan, Pierre C. Bellec

Unsolved

State evolution for gradient descent beyond the mean-field scaling

Mathematical StatisticsOptimization & Variational MethodsLearning Theory

Sourced from the work of Qiyang Han, Xiaocong Xu

Unsolved

Sharp characterization of misspecification robustness for debiased GD inference

Mathematical StatisticsOptimization & Variational MethodsLearning Theory

Sourced from the work of Qiyang Han, Xiaocong Xu

Unsolved

Generalization-error estimation beyond Gaussian designs

Mathematical StatisticsOptimization & Variational MethodsLearning Theory

Sourced from the work of Pierre C Bellec, Kai Tan

Unsolved

Early-stopping optimality without a U-shape risk assumption

Mathematical StatisticsOptimization & Variational MethodsLearning Theory

Sourced from the work of Pierre C Bellec, Kai Tan

UnsolvedNotable

Critical SNR for outlier emergence at fixed summary statistics

Mathematical StatisticsOptimization & Variational MethodsInformation Theory

Sourced from the work of Gerard Ben Arous, Reza Gheissari, Jiaoyang Huang, Aukosh Jagannath

UnsolvedNotable

Small-SNR no-outlier regime and monotonicity in SNR

Mathematical StatisticsOptimization & Variational MethodsInformation Theory

Sourced from the work of Gerard Ben Arous, Reza Gheissari, Jiaoyang Huang, Aukosh Jagannath

Unsolved

Sharp dynamic emergence thresholds for XOR/multilayer GMM classification

Mathematical StatisticsOptimization & Variational MethodsInformation Theory

Sourced from the work of Gerard Ben Arous, Reza Gheissari, Jiaoyang Huang, Aukosh Jagannath

Unsolved

Outlier theory beyond non-degeneracy/invertibility assumptions (ReLU and zero diagonal entries)

Mathematical StatisticsOptimization & Variational MethodsInformation Theory

Sourced from the work of Gerard Ben Arous, Reza Gheissari, Jiaoyang Huang, Aukosh Jagannath

Unsolved

Outlier characterization for unbounded link functions (e.g., phase retrieval)

Mathematical StatisticsOptimization & Variational MethodsInformation Theory

Sourced from the work of Gerard Ben Arous, Reza Gheissari, Jiaoyang Huang, Aukosh Jagannath

Unsolved

Regret Minimization in Heavy-Tailed Bandits with Unknown Distributional Parameters

Learning TheoryOptimization & Variational Methods

Posed by Gianmarco Genalti et al. (2025)

Unsolved

What is the Complexity of Joint Differential Privacy in Linear Contextual Bandits?

Learning TheoryOptimization & Variational MethodsTheoretical Computer Science

Posed by Achraf Azize et al. (2024)

Unsolved

Black-Box Reductions and Adaptive Gradient Methods for Nonconvex Optimization

Learning TheoryOptimization & Variational Methods

Posed by Xinyi Chen et al. (2024)

Unsolved

Optimal Rates for Stochastic Decision-Theoretic Online Learning Under Differentially Privacy

Learning TheoryOptimization & Variational MethodsTheoretical Computer Science

Posed by Bingshan Hu et al. (2024)

Unsolved

Anytime Convergence Rate of Gradient Descent

Learning TheoryOptimization & Variational Methods

Posed by Guy Kornowski et al. (2024)

Unsolved

Order Optimal Regret Bounds for Kernel-Based Reinforcement Learning

Learning TheoryOptimization & Variational Methods

Posed by Sattar Vakili (2024)

Unsolved

Convergence of single-timescale mean-field Langevin descent-ascent for two-player zero-sum games

Learning TheoryOptimization & Variational Methods

Posed by Guillaume Wang et al. (2024)

Unsolved

Polynomial linearly-convergent method for g-convex optimization?

Learning TheoryOptimization & Variational Methods

Posed by Christopher Criscitiello et al. (2023)

Unsolved

Regret Bounds for Noise-Free Kernel-Based Bandits

Learning TheoryOptimization & Variational Methods

Posed by Sattar Vakili (2022)

Unsolved

Do you pay for Privacy in Online learning?

Learning TheoryOptimization & Variational MethodsTheoretical Computer Science

Posed by Amartya Sanyal et al. (2022)

Unsolved

Finite-Time Instance Dependent Optimality for Stochastic Online Learning with Feedback Graphs

Learning TheoryOptimization & Variational Methods

Posed by Teodor Vanislavov Marinov et al. (2022)

Unsolved

Is There an Online Learning Algorithm That Learns Whenever Online Learning Is Possible?

Learning TheoryOptimization & Variational Methods

Posed by Steve Hanneke (2021)

Unsolved

Tight Online Confidence Intervals for RKHS Elements

Learning TheoryOptimization & Variational Methods

Posed by Sattar Vakili et al. (2021)

Unsolved

Can Single-Shuffle SGD be Better than Reshuffling SGD and GD?

Learning TheoryOptimization & Variational Methods

Posed by Chulhee Yun et al. (2021)

Unsolved

Model Selection for Contextual Bandits

Learning TheoryOptimization & Variational Methods

Posed by Dylan J. Foster et al. (2020)

Unsolved

Tight Convergence of SGD in Constant Dimension

Learning TheoryOptimization & Variational Methods

Posed by Tomer Koren et al. (2020)

Unsolved

Fast and Optimal Online Portfolio Selection

Learning TheoryOptimization & Variational Methods

Posed by Tim Van Erven et al. (2020)

Unsolved

Risk of Ruin in Multiarmed Bandits

Learning TheoryOptimization & Variational Methods

Posed by Filipo S. Perotto et al. (2019)

Unsolved

The Oracle Complexity of Convex Optimization with Limited Memory

Learning TheoryOptimization & Variational MethodsTheoretical Computer Science

Posed by Blake Woodworth et al. (2019)