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.

169,181 papers · 148 categories

Trend · papers per month

170339509678 · Jun 202019922001200920182026
48 results for burn-in demonstrations

SGD shows distinct phases in learning single-index models, achieving optimal sample complexity and regret.

problem Learning single-index models with SGD in adaptive data settings.
method Stochastic gradient descent (SGD) with an optimal learning rate schedule.
result SGD achieves near-optimal sample complexity and regret guarantees across both burn-in and learning phases.

ULA estimates covariance of log-concave distributions efficiently.

problem Estimating covariance matrices of log-concave distributions efficiently.
method Unadjusted Langevin algorithm (ULA) for sampling and covariance estimation.
result Sample complexity of single-chain ULA is smaller than that of parallel ULA by a logarithmic factor.

A new algorithm reduces memory and computational needs for reinforcement learning.

problem Memory and computational inefficiency in model-free reinforcement learning.
method Memory-Efficient Nash Q-Learning (ME-Nash-QL) for two-player zero-sum games.
result Proves ME-Nash-QL reduces space and sample complexity for tabular and long-horizon cases.

New bounds on trajectory safety in training models with Langevin Dynamics.

problem Bounding the probability of a model's trajectory staying away from a designated failure region.
method Analyzes Langevin dynamics on smooth, strongly convex loss landscapes, introducing shape-free and local relaxation bounds.
result The in-set probability relaxes to the static value after a burn-in time of order d, using only the global spectral gap of the loss.

Communication costs, resulting from synchronization requirements during learning, can greatly slow down many parallel machine learning algorithms. In this paper, we present a parallel Markov chain Monte Carlo (MCMC) algorithm in which subsets of data are processed independently, with very little communication. First, w…

2013-11-19abs ↗pdf ↗

Two algorithms learn Gaussian graphical models from Glauber dynamics trajectories.

problem Learning Gaussian graphical models from dependent data.
method Two complementary approaches: local edge-testing and burn-in/thinning reduction.
result Both approaches provide finite-sample recovery guarantees and empirical comparisons.

We present a general framework for accelerating a large class of widely used Markov chain Monte Carlo (MCMC) algorithms. Our approach exploits fast, iterative approximations to the target density to speculatively evaluate many potential future steps of the chain in parallel. The approach can accelerate computation of t…

2014-03-28abs ↗pdf ↗

Study bounds noise level in linear regression with dependent data.

problem Analyzing noise level in linear regression with dependent data.
method Derive upper bounds for random design linear regression with ββ-mixing data, without realizability assumptions.
result Correctly recovers the noise level of the problem, exhibiting graceful degradation with misspecification.

In this paper we address the following question: Can we approximately sample from a Bayesian posterior distribution if we are only allowed to touch a small mini-batch of data-items for every sample we generate?. An algorithm based on the Langevin equation with stochastic gradients (SGLD) was previously proposed to solv…

2012-06-27abs ↗pdf ↗

Restricted Boltzmann machines (RBMs) are powerful machine learning models, but learning and some kinds of inference in the model require sampling-based approximations, which, in classical digital computers, are implemented using expensive MCMC. Physical computation offers the opportunity to reduce the cost of sampling …

2013-12-18abs ↗pdf ↗

Enhanced MH algorithm reduces expensive function evaluations and improves sampling efficiency.

problem Computational expense of evaluating target distributions or likelihood functions, especially with big data.
method Accelerated MH algorithm using Bayesian optimization and Gaussian processes.
result Significant improvement in sampling efficiency and reduced function evaluations.

UCRL3 improves UCRL2's efficiency in reinforcement learning by reducing exploration.

problem Long burn-in phases in numerical experiments of UCRL2.
method UCRL3 uses state-of-the-art time-uniform concentration inequalities and adaptive support computation to tighten exploration.
result UCRL3 achieves a better numerical improvement over UCRL2 in standard environments.

Particle Metropolis-Hastings (PMH) allows for Bayesian parameter inference in nonlinear state space models by combining Markov chain Monte Carlo (MCMC) and particle filtering. The latter is used to estimate the intractable likelihood. In its original formulation, PMH makes use of a marginal MCMC proposal for the parame…

2013-11-04abs ↗pdf ↗

Particle MCMC is a class of algorithms that can be used to analyse state-space models. They use MCMC moves to update the parameters of the models, and particle filters to propose values for the path of the state-space model. Currently the default is to use random walk Metropolis to update the parameter values. We show …

2014-02-04abs ↗pdf ↗

New algorithm finds critical points in non-convex optimization with heavy-tailed gradients.

problem Non-convex stochastic optimization with heavy-tailed gradient estimates.
method Gradient clipping, momentum, and normalized gradient descent.
result High-probability convergence to critical points with best-known rates.

This work analyzes the convergence rate of unrolling for optimizing quadratic objectives.

problem The challenge of accurately computing Jacobians through optimization.
method Non-asymptotic convergence-rate analysis of unrolled differentiation for gradient descent and Chebyshev method.
result There is a trade-off between fast asymptotic convergence and immediate but slower convergence due to the learning rate.

This study provides an explicit expansion of KL divergence's gradient flow in Fisher-Rao geometry.

problem Sampling techniques struggle to traverse between modes in non-convex potential functions.
method Explicit expansion of KL divergence's gradient flow in Fisher-Rao geometry.
result The convergence rate to π is independent of the potential function.

Bayesian realized EGARCH models improve tail risk forecasting.

problem Forecasting tail risks in financial markets.
method Developed a Bayesian framework for realized EGARCH models, incorporating multiple realized volatility measures and using robust adaptive Metropolis algorithm for estimation.
result Standardized skewed Student-t distribution and sub-sampled realized range models outperform other models in tail risk forecasting.

New analysis shows SGD with noise doesn't leak more privacy with more iterations.

problem Privacy loss in noisy SGD with more iterations.
method Privacy Amplification by Iteration and Sampled Gaussian Mechanism.
result Privacy loss remains constant after a burn-in period, not increasing with more iterations.

The paper analyzes Adam and SGD in nonstationary optimization, revealing tradeoffs between noise and drift.

problem Analyzing Adam and SGD in nonstationary optimization problems.
method Theoretical analysis of Adam and SGD under non-stationary stochastic objectives, separating two regimes.
result Characterizes the tradeoff between noise and drift in Adam and SGD, revealing when adaptive step-sizing is beneficial or harmful.

The paper improves importance sampling and MCMC methods for complex distributions.

problem Improving sampling efficiency for distributions with atoms or heavy tails.
method Develops minimax optimal trial distributions and importance-tempered MCMC.
result Importance-tempered MCMC can be uniformly ergodic for certain distributions.

Spectral gradient methods outperform Euclidean in certain deep learning scenarios.

problem When do spectral gradient updates outperform Euclidean in deep learning?
method Layerwise condition comparing squared nuclear-to-Frobenius ratio to stable rank of activations.
result Spectral updates can be more effective than Euclidean in deep networks and transformers.

Near-optimal tests and confidence sequences for non-parametric data.

problem Flexible statistical inference and decision-making with non-parametric data.
method Classic delayed-start normal-mixture sequential probability ratio tests with asymptotic guarantees.
result Asymptotically optimal type-I error and expected rejection time guarantees.

New RL algorithm reduces sample complexity for optimal learning.

problem Achieving optimal learning with minimal samples in RL.
method Early-settled variance reduction method with Q-learning sequences.
result Near-optimal regret achieved with sample size SApoly(H)SA\,\mathrm{poly}(H).

BART improves predictive performance but slows down with more data.

problem Understanding and improving the computational efficiency of BART with large datasets.
method Asymptotic analysis of a modified BART sampler, focusing on hitting time of high posterior density sets.
result The convergence time of the BART sampler increases with the number of training samples due to multi-modality, but can be mitigated by increasing the number of trees or raising the sampler temperature.

D-REX learns reward functions from ranked demonstrations to beat the demonstrator's performance.

problem Limited performance of imitation learning compared to the demonstrator.
method Disturbance-based Reward Extrapolation (D-REX) that generates ranked demonstrations from behavioral cloning.
result D-REX significantly outperforms standard imitation learning approaches and beats the demonstrator's performance.

LEARN-SAM improves RL from sub-optimal demonstrations by localizing expert policies and selectively using demonstrations.

problem Improving RL from sub-optimal or sparse demonstrations.
method Local Ensemble and Reparameterization with Split and Merge of expert policies (LEARN-SAM).
result LEARN-SAM boosts learning speed and accuracy by selectively using demonstrations.

Unified reinforcement learning from imperfect demonstrations improves robustness.

problem Learning from imperfect expert demonstrations and interactions with the environment.
method Normalized Actor-Critic (NAC) algorithm that normalizes Q-function and uses same objective for both learning from demonstrations and interactive refinement.
result NAC outperforms existing baselines in several realistic driving games.

A framework helps reinforcement learning agents understand and decompose tasks from human demonstrations.

problem Sparse-reward tasks where demonstrations are used as sources of causal knowledge.
method Develops causal models through observation and reasons from this knowledge to decompose tasks.
result A basic implementation of Reasoning from Demonstration (RfD) is effective in sparse-reward tasks.

Novel framework learns policies from noisy expert demonstrations.

problem Learning effective policies with noisy expert demonstrations.
method Adaptive learning framework that jointly interacts with the environment and expert demonstrations, assigning weights to filter out noisy demonstrations.
result The proposed approach learns robustly with noisy demonstrations and achieves higher performance in fewer iterations.