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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

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69139208277 · Jun 202019922001200920172026
48 results for arm-pull dynamics

This paper studies Thompson sampling's arm-pull dynamics and inference, revealing key differences from UCB algorithms.

problem Understanding the precise arm-pull dynamics in Thompson sampling algorithms.
method Developed new approaches to analyze the arm-pull count process and noise processes, including inverse process and reparametrization methods.
result Arm-pull count is asymptotically deterministic only for suboptimal or unique optimal arms, revealing a unifying principle of stability.

Develops a framework for clustering and distribution matching with bandit feedback.

problem Clustering and distribution matching problems with limited feedback.
method General framework using KK-armed bandit model, Track-and-Stop method, and Frank--Wolfe algorithm.
result Average number of arm pulls matches lower bound, with asymptotic convergence to fundamental limit.

We extend the classic multi-armed bandit (MAB) model to the setting of noncompliance, where the arm pull is a mere instrument and the treatment applied may differ from it, which gives rise to the instrument-armed bandit (IAB) problem. The IAB setting is relevant whenever the experimental units are human since free will…

2017-05-21abs ↗pdf ↗

New MAB model incentivizes user arm-pulling with self-reinforcing preferences.

problem Balancing exploration and exploitation in recommender systems with incentivized user preferences.
method Proposes a new MAB model with random arm selection and two policies: At-Least-nn Explore-Then-Commit and UCB-List.
result Achieves O(logT)O(log T) expected regret and O(logT)O(log T) expected payment over a time horizon TT.

UCB algorithms improve on bandit problems with precise regret analysis and adaptive inference.

problem Understanding the performance and statistical inference of UCB algorithms in multi-armed bandit problems.
method Deterministic characterization of arm pulls and precise regret analysis.
result UCB algorithms' maximal regret deviates from minimax regret by a logarithmic factor, and the Lai-Robbins formula is exact only under specific conditions.

Motivated by drug design, we consider the best-arm identification problem in generalized linear bandits. More specifically, we assume each arm has a vector of covariates, there is an unknown vector of parameters that is common across the arms, and a generalized linear model captures the dependence of rewards on the cov…

2019-05-20abs ↗pdf ↗

New algorithm tackles resource allocation in multi-armed bandits to balance speed and throughput.

problem Balancing speed and throughput in stochastic multi-armed bandits with limited resources.
method Proposes an algorithm that trades off between information accumulation and throughput.
result Upper bounds the time taken to find the best arm with a given target success probability.

Learning preferences implicit in the choices humans make is a well studied problem in both economics and computer science. However, most work makes the assumption that humans are acting (noisily) optimally with respect to their preferences. Such approaches can fail when people are themselves learning about what they wa…

2019-01-24abs ↗pdf ↗

A new algorithm improves sample complexity for thresholding in Monte Carlo Tree Search.

problem Determining if the root node value of a tree is at least a given threshold.
method Developed a δ-correct sequential sampling algorithm based on the Track-and-Stop strategy.
result Ratio-based modification of D-Tracking strategy reduces sample complexity and computational cost.

This paper studies active learning in the context of robust statistics. Specifically, we propose a variant of the Best Arm Identification problem for \emph{contaminated bandits}, where each arm pull has probability ε\varepsilon of generating a sample from an arbitrary contamination distribution instead of the true und…

2018-02-26abs ↗pdf ↗

The paper tackles a bandit problem with infinitely many arms per group, aiming to identify the group with the highest quantile reward.

problem Max-quantile group bandit problem with infinitely many arms per group.
method Two-step algorithm: first request arms from each group, then apply a finite-arm max-quantile bandit algorithm.
result Characterization of instance-dependent and worst-case regret, with matching lower bounds.

Optimizing rewards under budget constraints with correlated costs and rewards.

problem Maximizing total expected reward under a budget constraint on total cost with correlated and potentially heavy-tailed cost-reward pairs.
method Proposes algorithms exploiting correlation between cost and reward via linear minimum mean-square error estimation to achieve tight regret bounds.
result Achieves O(logB)O(\log B) regret for a budget B>0B>0 under certain moment conditions.

We propose a novel formulation of group fairness with biased feedback in the contextual multi-armed bandit (CMAB) setting. In the CMAB setting, a sequential decision maker must, at each time step, choose an arm to pull from a finite set of arms after observing some context for each of the potential arm pulls. In our mo…

2019-12-09abs ↗pdf ↗

New algorithm finds high-reward combinatorial sets with fewest pulls.

problem Finding high-reward combinatorial sets with unknown individual arm rewards.
method Successive acceptance and elimination based on combinatorial structure.
result Algorithm requires minimal combinatorial oracle calls, making it practical for large problems.

New algorithms for streaming bandits with limited memory.

problem Optimizing decisions in a stream of uncertain outcomes with limited memory.
method Developed algorithms for minimizing regret and identifying the best arm under bounded memory constraints.
result Upper and lower bounds on sample complexity for best-arm identification algorithms.

A bandit algorithm reduces regret in noisy, communication-constrained feedback.

problem Distributed stochastic multi-armed bandit with noisy, communication-constrained feedback.
method Proposes a multi-phase bandit algorithm, UE-UCB++, that matches an information-theoretic lower bound.
result Matches an information-theoretic lower bound of Ω(√(KT/σ²)) on the minimax regret.

A federated learning algorithm tackles linear bandits with adversarial actions, achieving optimal regret bounds.

problem Federated linear bandits with finite adversarial action sets.
method FedSupLinUCB algorithm, extending SupLinUCB and OFUL principles.
result Achieves a total regret of ildeO(dT) ilde{O}(\sqrt{d T}), matching minimax lower bound and being order-optimal.

New algorithm CROP achieves asymptotic optimality with bounded regret.

problem Optimistic algorithms fail to achieve asymptotic instance-dependent regret optimality.
method CRush Optimism with Pessimism (CROP) algorithm that eliminates optimistic hypotheses.
result CROP achieves constant-factor asymptotic optimality and bounded regret.

In this paper, we introduce a distributed version of the classical stochastic Multi-Arm Bandit (MAB) problem. Our setting consists of a large number of agents nn that collaboratively and simultaneously solve the same instance of KK armed MAB to minimize the average cumulative regret over all agents. The agents can co…

2019-10-04abs ↗pdf ↗

Opt-BBAI identifies the best arm with minimal batches and pulls, optimizing both sample and batch complexity.

problem Batched best arm identification (BBAI) problem, aiming to minimize policy switches and resource usage.
method Proposed Opt-BBAI algorithm, achieving near-optimal sample and batch complexity in non-asymptotic settings.
result First algorithm to achieve near-optimal sample and batch complexity in non-asymptotic settings.

In this paper, we introduce Ballooning Multi-Armed Bandits (BL-MAB), a novel extension of the classical stochastic MAB model. In the BL-MAB model, the set of available arms grows (or balloons) over time. In contrast to the classical MAB setting where the regret is computed with respect to the best arm overall, the regr…

2020-01-24abs ↗pdf ↗

New algorithm tackles multi-armed bandit with arbitrary delays and general bounded losses.

problem Scale-free adversarial multi-armed bandit with arbitrary feedback delays.
method SFD-INF combines convex combination trick and doubling/skipping technique.
result Achieves adaptive regret bounds for non-negative and general scale-free losses.

PAC best arm identification with a deadline, improving efficiency over sequential methods.

problem Identifying an optimal arm under a fixed time constraint.
method Elastic Batch Racing (EBR) algorithm for (ε,δ)(ε, δ)-PAC best arm identification under a deadline.
result EBR is optimal with respect to two hardness results and outperforms sequential methods.

New algorithm uses machine learning to predict rewards for decision-making problems.

problem Sequential decision-making under uncertainty with scarce online data.
method Machine Learning-Assisted Upper Confidence Bound (MLA-UCB) algorithm.
result Proves to improve cumulative regret even with biased surrogate rewards.

New algorithm tackles batched stochastic linear bandits with 1-bit communication constraints.

problem Stochastic linear bandits with 1-bit communication constraints.
method Phased-elimination algorithms based on G-optimal designs and 1-bit mean estimation.
result Achieves near-optimal regret bounds for broad scaling regimes.

Study on 2-valued dynamics on complex plane, showing some dynamics can't be group actions.

problem Whether 2-valued dynamics can be defined by the action of a 2-valued group.
method Construction of examples of dynamics that are or are not group actions.
result Some 2-valued dynamics on complex plane cannot be defined by the action of a 2-valued group.

The paper studies dynamic star-shaped risk measures and their representation.

problem Representing dynamic star-shaped risk measures and their properties.
method Representation theorems for dynamic monetary and star-shaped risk measures.
result Dynamic star-shaped risk measures can be represented as the lower envelope of a family of dynamic convex risk measures.

DOODL learns shared spectral dynamics across related dynamical systems.

problem Learning independent dynamical operators for each system limits discovery of shared structure.
method DOODL learns a dictionary of characteristic spectral dynamics on a manifold of related systems.
result DOODL achieves errors one to two orders of magnitude lower than independent operator estimation methods.

We propose a new class of mappings, called Dynamic Limit Growth Indices, that are designed to measure the long-run performance of a financial portfolio in discrete time setup. We study various important properties for this new class of measures, and in particular, we provide necessary and sufficient condition for a Dyn…

2013-12-04abs ↗pdf ↗

Unified analysis of DLNs using DMFT reveals dynamics of loss convergence and generalization trade-offs.

problem Understanding the overall dynamics of diagonal linear networks (DLNs) in neural network training.
method Dynamical Mean-Field Theory (DMFT) applied to DLNs.
result Derives low-dimensional effective process capturing high-dimensional gradient flow dynamics.