Research
On-device research index

arXiv research

A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

168,695 papers · 148 categories

Trend · papers per month

97194290387 · Jun 202019922001200920172026
48 results for optimistic bounds

Optimistic Hedge achieves optimal regret bounds in two-player zero-sum games.

problem Achieving optimal regret bounds for optimistic Hedge in two-player zero-sum games.
method Refined regret analysis and optimization problem formulation.
result Optimistic Hedge achieves O(logmlogn)O(\sqrt{\log m \log n}) regret bounds, matching upper and lower bounds.

Optimistic bounds for multi-output learning using self-bounding Lipschitz condition.

problem Learning vector-valued functions from supervised data.
method Introducing self-bounding Lipschitz condition and proving optimistic bounds using local Rademacher complexity and Srebro's inequality.
result Minimax optimal generalization bounds for multi-output learning, up to logarithmic factors.

Novel approach to universal online learning for bounded losses, closing open problems.

problem Characterizing processes for universal online learning under non-i.i.d. conditions.
method Characterization of processes admitting strong and weak universal learning, introduction of optimistically universal learning rule.
result Introduction of a novel 1NN algorithm that is optimistically universal for bounded losses.

Optimistic PPO variant solves linear MDPs with improved regret bound.

problem Understanding theoretical limits of PPO in linear MDPs.
method Proposes an optimistic variant of PPO for episodic adversarial linear MDPs with full-information feedback.
result Establishes a ildeO(d3/4H2K3/4) ilde{\mathcal{O}}(d^{3/4}H^2K^{3/4}) regret bound.

This paper establishes that optimistic algorithms attain gap-dependent and non-asymptotic logarithmic regret for episodic MDPs. In contrast to prior work, our bounds do not suffer a dependence on diameter-like quantities or ergodicity, and smoothly interpolate between the gap dependent logarithmic-regret, and the $\wid…

2019-05-09abs ↗pdf ↗

Improved regret bounds for online convex optimization under stochastic and adversarial settings.

problem Interpolating between stochastic and adversarial online convex optimization.
method Optimistic online mirror descent (OMD) for the Stochastically Extended Adversarial (SEA) model.
result Established new regret bounds for various function classes.

Optimistic RL algorithms are simplified for deep RL with competitive performance.

problem Achieving accurate optimism in model-based RL for large-scale problems.
method Interpreting scalable optimistic model-based algorithms as solving a tractable noise augmented MDP.
result Competitive regret bound of ildeO(SHAT) ilde{\mathcal{O}}( |\mathcal{S}|H\sqrt{|\mathcal{A}| T } ) for Gaussian noise augmentation.

A generalized optimistic method for saddle point problems with improved complexity.

problem Solving convex-concave saddle point problems efficiently.
method Proposes a generalized optimistic method that includes the optimistic gradient method as a special case, handling constrained saddle point problems with composite objective functions and arbitrary norms.
result Best-known global iteration complexity bounds for first-, second-, and higher-order methods.

Optimistic method adapted for faster convex-concave min-max problems.

problem Solving convex-concave min-max optimization problems efficiently.
method Adaptive, line search-free second-order methods combining optimistic updates and second-order information.
result Achieves optimal convergence rate without line search or backtracking.

Optimistic algorithm reduces regret and constraint violations in online convex optimization with adversarial constraints.

problem Online convex optimization with adversarial constraints.
method Improved algorithm using accurate predictions of loss and constraint functions.
result Improved bounds on regret and cumulative constraint violations.

Study optimizes linear regression analysis for high-dimensional settings.

problem Understanding high-dimensional linear regression with interpolation and regularization.
method Localized uniform convergence analysis of optimistic rates for linear regression.
result Recover guarantees for ridge and LASSO regression under random designs.

Proposes H-UCRL for efficient model-based RL with sublinear regret.

problem Greedy policy exploration in model-based RL ignores epistemic uncertainty.
method Reparameterizes plausible models, hallucinates control, augments input space, solves with greedy planners.
result H-UCRL achieves provably sublinear regret for Gaussian Process models.

New algorithm achieves data-dependent regret bounds in MDPs with unknown transitions.

problem Achieving best-of-both-worlds guarantees with data-dependent regret bounds in MDPs with unknown transitions.
method Optimistic follow-the-regularized-leader algorithm with new optimistic Q-function estimators and transition bonus.
result First-order, second-order, and path-length bounds with polylog(T) regret in the stochastic regime.

We consider the problem of online planning in a Markov Decision Process when given only access to a generative model, restricted to open-loop policies - i.e. sequences of actions - and under budget constraint. In this setting, the Open-Loop Optimistic Planning (OLOP) algorithm enjoys good theoretical guarantees but is …

2019-04-09abs ↗pdf ↗

New algorithms reduce regret in online MDPs by adapting to data and variance.

problem Adapting to both adversarial and stochastic environments in online MDPs.
method Develops algorithms based on global optimization and policy optimization, using optimistic follow-the-regularized-leader with log-barrier regularization.
result Achieves refined data-dependent and variance-dependent regret bounds.

We address the issue of limit cycling behavior in training Generative Adversarial Networks and propose the use of Optimistic Mirror Decent (OMD) for training Wasserstein GANs. Recent theoretical results have shown that optimistic mirror decent (OMD) can enjoy faster regret rates in the context of zero-sum games. WGANs …

2017-10-31abs ↗pdf ↗

We propose a new variant of AMSGrad, a popular adaptive gradient based optimization algorithm widely used for training deep neural networks. Our algorithm adds prior knowledge about the sequence of consecutive mini-batch gradients and leverages its underlying structure making the gradients sequentially predictable. By …

2019-03-04abs ↗pdf ↗

PROPO tackles non-stationary MDPs with efficient policy optimization.

problem Non-stationary MDPs with varying reward and transition kernels.
method PROPO, a periodic restarted optimistic policy optimization algorithm with sliding-window-based policy evaluation and improvement.
result PROPO achieves near-optimal performance in non-stationary MDPs.

Proposes Optimistic Pessimistically Initialised Q-Learning (OPIQ) for better exploration in RL.

problem Pessimistic initialisation of Q-values in deep RL leads to poor exploration performance.
method Augments pessimistically initialised Q-values with count-based bonuses to ensure optimism.
result OPIQ outperforms non-optimistic DQN variants in hard exploration tasks.

We discuss the relative merits of optimistic and randomized approaches to exploration in reinforcement learning. Optimistic approaches presented in the literature apply an optimistic boost to the value estimate at each state-action pair and select actions that are greedy with respect to the resulting optimistic value f…

2017-06-13abs ↗pdf ↗

Optimistic estimate predicts best fitting performance of nonlinear models.

problem Evaluating the potential of nonlinear models in fitting.
method Proposes an optimistic estimate to quantify the smallest sample size for fitting nonlinear models.
result Predicts specific subsets of targets that can be fitted at overparameterization.

Bayesian optimisation (BO) is a well-known efficient algorithm for finding the global optimum of expensive, black-box functions. The current practical BO algorithms have regret bounds ranging from O(logNN)\mathcal{O}(\frac{logN}{\sqrt{N}}) to O(eN)\mathcal O(e^{-\sqrt{N}}), where NN is the number of evaluations. This paper exp…

2021-05-10abs ↗pdf ↗

New algorithm reduces regret in sequential decision-making problems.

problem Balancing exploration and exploitation in online sequential decision problems.
method Variational Bayesian optimistic sampling (VBOS) for optimizing policies.
result VBOS achieves ildeO(AT) ilde O(\sqrt{AT}) Bayesian regret for stochastic multi-armed bandits.

New RL algorithm tackles nonstationary MDPs with linear approximations and varying rewards.

problem Nonstationary reinforcement learning with evolving reward and state transition functions.
method Developed a new algorithm LSVI-UCB-Restart with periodic restart, and parameter-free Ada-LSVI-UCB-Restart for unknown variation budgets.
result First minimax dynamic regret lower bound for nonstationary linear MDPs and linear MDPs lower bound.

Optimistic NPG improves policy optimization in online RL with efficient sample complexity.

problem Limited theoretical understanding of policy optimization, especially in online RL.
method Combines natural policy gradient with optimistic policy evaluation.
result Achieves optimal dimension dependence sample complexity for learning near-optimal policies.

Improved model-free reinforcement learning with decision-estimation coefficient.

problem Interactive decision making, including structured bandits and reinforcement learning.
method Combining Estimation-to-Decisions with optimistic estimation to achieve better regret bounds.
result Regret bounds for model-free reinforcement learning with value function approximation.

We show how to take any two parameter-free online learning algorithms with different regret guarantees and obtain a single algorithm whose regret is the minimum of the two base algorithms. Our method is embarrassingly simple: just add the iterates. This trick can generate efficient algorithms that adapt to many norms s…

2019-02-24abs ↗pdf ↗

An algorithm for maximizing rewards under linear cost constraints.

problem Maximizing rewards while adhering to cost constraints in a linear bandit problem.
method Proposes an upper-confidence bound algorithm called optimistic pessimistic linear bandit (OPLB) for constrained contextual linear bandits.
result Proves an O~(dTτc0)\widetilde{\mathcal{O}}(\frac{d\sqrt{T}}{τ-c_0}) bound on regret for the proposed algorithm.

We give a simple optimistic algorithm for which it is easy to derive regret bounds of O~(tmixSAT)\tilde{O}(\sqrt{t_{\rm mix} SAT}) after TT steps in uniformly ergodic Markov decision processes with SS states, AA actions, and mixing time parameter tmixt_{\rm mix}. These bounds are the first regret bounds in the general, non-epi…

2018-08-06abs ↗pdf ↗

Optimistic Thompson Sampling reduces regret in unknown multi-player games.

problem Navigating uncertainty in unknown multi-player games with strategic decision-making.
method Introduces Thompson Sampling algorithms that exploit opponents' actions and reward structures.
result Achieves over tenfold improvements in experimental budgets with logarithmic regret bound.