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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.

168,742 papers · 148 categories

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53105158210 · Jun 202019922001200920172026
48 results for independent arms

Paper improves CMAB regret bounds by reducing batch-size dependency.

problem Reducing batch-size dependency in combinatorial semi-bandits.
method Developed BCUCB-T and SESCB algorithms with new TPVM conditions.
result Significantly improved regret bounds for various applications.

This paper extends the MAB problem to consider risk-reward tradeoffs.

problem Maximizing reward while accounting for risk in multi-armed bandit problems.
method Introduced the Risk Aware Lower Confidence Bound (RALCB) algorithm to solve the mean-variance MAB problem.
result The RALCB algorithm performs better than the algorithm in Sani et al. (2012) in both independent and dependent scenarios.

Thompson Sampling is at most twice as bad as any other policy in Bayesian bandit models.

problem Optimizing selection of the best arm in Bayesian bandit models with independent latent processes.
method Thompson Sampling approach applied to models with independent latent arm processes.
result Thompson Sampling makes at most twice the expected number of mistakes compared to any other policy.

Paper tackles identifying an odd arm in a multi-armed bandit with restless Markov processes and trembling hand.

problem Identifying an odd arm in a multi-armed bandit with restless Markov processes and trembling hand.
method Derive asymptotic lower bound on expected time to identify the odd arm, stitch together parameterised solutions to MDPs.
result First known asymptotic lower bound on expected time to identify the odd arm, with vanishing error probability.

We consider a problem of stochastic online learning with general probabilistic graph feedback, where each directed edge in the feedback graph has probability pijp_{ij}. Two cases are covered. (a) The one-step case, where after playing arm ii the learner observes a sample reward feedback of arm jj with independent prob…

2019-03-04abs ↗pdf ↗

New algorithms ensure fair selection in combinatorial semi-bandit with unrestricted delays.

problem Fair selection in stochastic combinatorial semi-bandit with delayed feedback.
method Introduced merit-based fairness constraints and new bandit algorithms for reward and fairness.
result Achieved sublinear expected reward and fairness regrets with dependence on delay distribution quantiles.

The paper tackles resource allocation for arms with unknown and random rewards, achieving optimal regret bounds.

problem Allocating resources on arms with unknown and random rewards.
method Developed two algorithms with optimal regret bounds for b[0,1]b \in [0,1], demonstrating a phase transition at b=1/2b=1/2.
result Achieved optimal gap-dependent and gap-independent regret bounds for b[0,1]b \in [0,1].

We analyze the KK-armed bandit problem where the reward for each arm is a noisy realization based on an observed context under mild nonparametric assumptions. We attain tight results for top-arm identification and a sublinear regret of O~(T1+D2+D)\widetilde{O}\Big(T^{\frac{1+D}{2+D}}\Big), where DD is the context dimension, f…

2018-01-05abs ↗pdf ↗

We study the stochastic multi-armed bandit problem in the case when the arm samples are dependent over time and generated from so-called weak $\cC$-mixing processes. We establish a $\cC-$Mix Improved UCB agorithm and provide both problem-dependent and independent regret analysis in two different scenarios. In the first…

2019-06-25abs ↗pdf ↗

ARMS improves gradient estimation for binary variables using antithetic samples.

problem Estimating gradients for binary variables in discrete latent variable models.
method ARMS uses antithetic samples generated by a copula to estimate gradients more efficiently and unbiasedly.
result ARMS outperforms competing methods in training generative models and optimizing variational bounds.

New lower bounds for combinatorial multi-armed bandits for general reward functions.

problem Maximizing reward in sequential decisions with sets of arms.
method Proved tight regret lower bounds for all smooth reward functions under mild assumptions.
result Lower bounds are tight up to log-factors for monotone reward functions.

Study best arm identification in restless Markov multi-armed bandits with state-dependent transitions.

problem Identify the best arm in a multi-armed bandit with time-varying states.
method Propose a sequential policy to select arms without knowing their exact TPMs.
result Upper and lower bounds on expected time to find the best arm match in a special case.

Unified meta algorithms estimate various distribution functionals in infinite-armed bandits.

problem Estimating various distribution functionals in infinite-armed bandits.
method Unified meta algorithms for offline and online settings, achieving optimal sample complexities.
result Online estimation offers significant advantage for certain distribution functionals.

We study how the regret guarantees of nonstochastic multi-armed bandits can be improved, if the effective range of the losses in each round is small (e.g. the maximal difference between two losses in a given round). Despite a recent impossibility result, we show how this can be made possible under certain mild addition…

2017-05-15abs ↗pdf ↗

Study best arm identification in restless bandits with unknown TPMs.

problem Identify the best arm with fixed confidence in restless bandits with unknown TPMs.
method Proposed a policy for best arm identification and proved its expected stopping time matches the lower bound.
result The state-action visitation proportions match the optimal proportions under any asymptotically optimal policy.

Adaptive algorithms minimize regret in matching markets with contextual arm preferences.

problem Minimizing regret in matching markets with context-dependent player utilities.
method Developed adaptive algorithms for stochastic and adversarial contexts, providing upper and lower bounds.
result Achieved sublinear regret bounds for both stochastic and adversarial contexts.

Optimism stabilizes Thompson Sampling for adaptive inference in multi-armed bandits.

problem Subtle inferential properties of Thompson Sampling under adaptive data collection.
method Introduced optimism as a key mechanism to restore stability and validity of inference.
result Suitably implemented optimism stabilizes Thompson Sampling and enables asymptotically valid Wald inference.

New algorithm tackles stochastic bandits with varying arm-dependent delays.

problem Applying existing algorithms to stochastic delayed bandit settings is restricted by strong assumptions on delay distributions.
method Proposes a simple UCB-based algorithm called PatientBandits that weakens assumptions on delay distributions.
result Provides bounds on regret and performance lower bounds for the PatientBandits algorithm.

This paper extends combinatorial semi-bandits to graph feedback, improving regret bounds.

problem Adversarial combinatorial semi-bandits with graph feedback.
method Introduced graph feedback in combinatorial semi-bandits, using convexified actions and online stochastic mirror descent.
result Optimal regret scales as ST+αSTS\sqrt{T}+\sqrt{αST}, interpolating between full and semi-bandit feedback.

Optimal best arm identification for multi-objective bandits with fixed error probability.

problem Identifying the best arm for each of multiple objectives with fixed confidence.
method Surrogate proportions to sample arms at each time step, eliminating max-min optimisation.
result Asymptotically optimal algorithm for multi-objective best arm identification.

Study on bandit problem with fixed number of arm types, achieving optimal regret bounds.

problem Stochastic multi-armed bandit problem with a fixed number of arm types.
method Proposes algorithms achieving optimal regret bounds for the problem.
result Achieves $\mathcal{O}\left( \log n ight)$ instance-dependent regret and $ ilde{\mathcal{O}}\left( \sqrt{n} ight)$ instance-independent regret.

Algorithm identifies best arm in bandit game with variance consideration.

problem Identifying the best arm in a stochastic multi-armed bandit game with varying variances.
method Adaptive algorithm using grouped median elimination to explore gaps and variances.
result Guarantees to output the best arm with probability (1-δ) using optimal number of samples.

In this paper, we introduce a new online decision making paradigm that we call Thresholding Graph Bandits. The main goal is to efficiently identify a subset of arms in a multi-armed bandit problem whose means are above a specified threshold. While traditionally in such problems, the arms are assumed to be independent, …

2019-05-22abs ↗pdf ↗

Proposes a new semi-parametric framework for batched bandits with covariates.

problem Sequential decision-making with batched feedback and contextual information.
method Batched single-Index Dynamic binning and Successive arm elimination (BIDS) using single-index regression.
result Achieves minimax-optimal rates for nonparametric batched bandits.

We consider stochastic multi-armed bandit problems with complex actions over a set of basic arms, where the decision maker plays a complex action rather than a basic arm in each round. The reward of the complex action is some function of the basic arms' rewards, and the feedback observed may not necessarily be the rewa…

2013-11-03abs ↗pdf ↗

The paper tackles noisy multi-armed bandit problems with improved regret guarantees.

problem Tackling noisy evaluations in multi-armed bandit problems.
method Derives different algorithmic approaches and theoretical guarantees based on the type of observation functions.
result Improved regret guarantees for noisy linear functions of true rewards.

New algorithm reduces regret in multi-agent bandits with malicious agents.

problem Collaboration between honest and malicious agents in multi-armed bandits.
method Dynamic reduction of communication with malicious agents, learning who is malicious.
result Algorithm reduces regret even with a single malicious agent, assuming mm is small compared to KK.

In this paper, we investigate the impact of diverse user preference on learning under the stochastic multi-armed bandit (MAB) framework. We aim to show that when the user preferences are sufficiently diverse and each arm can be optimal for certain users, the O(log T) regret incurred by exploring the sub-optimal arms un…

2019-01-23abs ↗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.

Optimal top-2 method improves best arm identification with reduced error.

problem Identifying the arm with the highest mean in a set of arms.
method A novel top-2 algorithm that pulls the empirical best arm with probability β and the challenger arm otherwise.
result The proposed algorithm matches the information theoretic lower bound on sample complexity as δ approaches 0.

The paper improves bandit algorithms by incorporating random-effect models.

problem Improving statistical efficiency in multi-armed bandit problems with misspecified priors.
method Introduces a random-effect model to bandits, estimating arm means and designing a UCB algorithm ReUCB.
result Derives an upper bound on the Bayes regret of ReUCB, showing improved performance over Thompson sampling.

Optimal algorithm for latent bandits with cluster structure reduces regret to nearly optimal.

problem Maximizing cumulative rewards in a multi-armed bandit problem with latent clusters.
method LATTICE algorithm exploiting cluster structure and arm information.
result Minimax optimal regret of O((M+N)T)O(\sqrt{(\mathsf{M}+\mathsf{N})\mathsf{T}}) with O(logT)O(\log{\mathsf{T}}) calls to matrix completion oracle.

New bounds for bandits with graph feedback, improving previous results.

problem Adversarial multi-armed bandits with graph feedback, focusing on small-loss bounds.
method Developed algorithms with regret bounds ildeO(κL)\mathcal{ ilde{O}}(\sqrt{κL_*}) and ildeO(min{αT,κL})\mathcal{ ilde{O}}(\min\{\sqrt{αT}, \sqrt{κL_*}\}).
result Significant improvement and extension of previous results by Lykouris et al. (2018).

We consider the restless Markov bandit problem, in which the state of each arm evolves according to a Markov process independently of the learner's actions. We suggest an algorithm that after TT steps achieves O~(T)\tilde{O}(\sqrt{T}) regret with respect to the best policy that knows the distributions of all arms. No ass…

2012-09-12abs ↗pdf ↗