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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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113227340453 · Jun 202019922001200920172026
48 results for strong observability

We observe that the strong slope conjecture implies that the degree of the colored Jones polynomial detects all torus knots. As an application we obtain that an adequate knot that has the same colored Jones polynomial degrees as a torus knot must be a (2,q)(2,q)-torus knot.

2018-08-24abs ↗pdf ↗

The paper solves robust learning of Gaussian mixtures with nearly optimal guarantees.

problem Learning a high-dimensional Gaussian mixture model with corrupted samples.
method Introduces a new framework called strong observability to circumvent the challenge of learning individual components.
result Achieves optimal robustness guarantees of εε in total variation distance for any constant number of components.

Improved averaging method for noisy observations converges strongly.

problem Noisy observations from random dynamical systems require stable estimates.
method Introduced pp-EMA, a modified exponential moving average with subharmonic weight decay.
result Stochastic convergence guarantees for pp-EMA under mild assumptions.

Regularization plays an important role in generalization of deep neural networks, which are often prone to overfitting with their numerous parameters. L1 and L2 regularizers are common regularization tools in machine learning with their simplicity and effectiveness. However, we observe that imposing strong L1 or L2 reg…

2018-11-20abs ↗pdf ↗

Linear recurrent networks explain reinforcement learning performance in partially observable settings.

problem Understanding why linear recurrent networks work in reinforcement learning with partial observability.
method Constructed and studied two linear filters for HMMs and action-controlled HMMs.
result Linear filters serve as sufficient statistics and reduce state ambiguity, explaining empirical reinforcement learning success.

The standard linear and logistic regression models assume that the response variables are independent, but share the same linear relationship to their corresponding vectors of covariates. The assumption that the response variables are independent is, however, too strong. In many applications, these responses are collec…

2019-05-08abs ↗pdf ↗

A new adaptive splitting method improves accuracy for Cox-Ingersoll-Ross model.

problem Improving numerical solution accuracy for Cox-Ingersoll-Ross model.
method Adaptive splitting method over deterministic and random meshes, with uniform moment bound and strong error results.
result Uniform moment bound and strong error results of order 1/4 in L1 and L2 for κθ>σ^2, and order 1 for large noise.

Paper analyzes weak-to-strong generalization in CNNs, identifying data-scarce and data-abundant regimes.

problem Weak-to-strong generalization in CNNs trained on weak models.
method Formal analysis of gradient descent dynamics in data-scarce and data-abundant regimes.
result Identifies two regimes and distinct mechanisms of generalization in each.

Method generates joint posterior samples of source and foreground mass distributions for gravitational lensing.

problem Challenging inference problem for high-resolution, high signal-to-noise ratio gravitational lensing.
method Combines diffusion-based generative modeling and recurrent inference machines.
result Can model realistic gravitational lensing simulations down to the noise level.

Study proves stability of big bang singularity in complex system.

problem Stability of Kasner solutions in Einstein-Maxwell-scalar field-Vlasov system.
method Detailed mathematical structures and new delicate arguments.
result Nonlinear stability with Kasner exponents in full strong sub-critical regime.

FastAdaBelief improves convergence rate of AdaBelief by exploiting strong convexity.

problem Improving convergence rate of AdaBelief without sacrificing generalization ability.
method Designing FastAdaBelief that adjusts step size considering strong convexity.
result Proves O(logT)O(\log T) regret bound for FastAdaBelief.

We study the problem of efficiently estimating the effect of an intervention on a single variable (atomic interventions) using observational samples in a causal Bayesian network. Our goal is to give algorithms that are efficient in both time and sample complexity in a non-parametric setting. Tian and Pearl (AAAI `02) h…

2020-02-11abs ↗pdf ↗

W2S FT often outperforms weak teachers due to low intrinsic dimensionality.

problem Understanding why weak-to-strong finetuning outperforms weak models.
method Analyzing W2S in ridgeless regression setting, focusing on variance reduction.
result Weak teacher's variance is inherited by strong student in shared feature subspace, reduced in discrepancy subspace.

The capitalization-weighted total relative variation i=1d0μi(t)dlogμi(t)\sum_{i=1}^d \int_0^\cdot μ_i (t) \mathrm{d} \langle \log μ_i \rangle (t) in an equity market consisting of a fixed number dd of assets with capitalization weights μi()μ_i (\cdot) is an observable and nondecreasing function of time. If this observable of the market …

2016-08-22abs ↗pdf ↗

MobILE learns from expert demonstrations without access to actions, achieving strong performance guarantees.

problem Imitation Learning from Observations alone (ILFO) where actions are not observed.
method MobILE integrates optimism in the face of uncertainty into distribution matching IL framework, trading off exploration and imitation.
result MobILE provides strong performance guarantees for certain MDP dynamics and demonstrates efficacy on OpenAI Gym tasks.

For an affine two factor model, we study the asymptotic properties of the maximum likelihood and least squares estimators of some appearing parameters in the so-called subcritical (ergodic) case based on continuous time observations. We prove strong consistency and asymptotic normality of the estimators in question.

2013-02-14abs ↗pdf ↗

TASC improves synthetic control for time-series data with trends.

problem Inability of existing SC methods to fully utilize temporal structure in time-series data.
method TASC uses a state-space model with a constant trend and Kalman filter for counterfactual inference.
result TASC offers advantages in settings with strong temporal trends and high observation noise.

In many areas, practitioners seek to use observational data to learn a treatment assignment policy that satisfies application-specific constraints, such as budget, fairness, simplicity, or other functional form constraints. For example, policies may be restricted to take the form of decision trees based on a limited se…

2017-02-09abs ↗pdf ↗

The paper reveals three mechanisms for weak-to-strong generalization.

problem Understanding the mechanisms behind weak-to-strong generalization in imperfect labeling scenarios.
method Theoretical analysis of simple models including ridge regression and weighted ridge regression, and a nonlinear multi-index setting.
result A student model can compensate for a teacher's under-regularization and achieve lower test error.

The paper cleans label noise in supervised classification using Bernoulli sampling.

problem Label noise degrades supervised classifier performance.
method Proposes a label noise cleaning method based on Bernoulli random sampling.
result The method separates clean and noisy observations without prior label information.

The u-plane integral is the contribution of the Coulomb branch to correlation functions of N=2 gauge theory on a compact four-manifold. We consider the u-plane integral for correlators of point and surface observables of topologically twisted theories with gauge group SU(2), for an arbitrary four-manifold with (b1,b2+)…

2019-10-29abs ↗pdf ↗

New framework tackles stochastic latent subgroup heterogeneity in online decision-making.

problem Stochastic latent heterogeneity in online decision-making where individual responses vary with unobserved subgroups.
method Latent heterogeneous bandit framework using EM-greedy algorithm to learn subgroup probabilities and reward parameters.
result Achieves optimal estimation and classification guarantees, revealing a fundamental stochastic barrier in online decision-making.

This paper studies statistical estimation in optional regression models.

problem Estimating parameters in regression models with optional semimartingale processes.
method Structural least squares (LS) estimates and their sequential versions.
result Strong consistency of LS-estimates and fixed accuracy of sequential LS-estimates.

FMI uses matching to mimic interventions for causal feature learning.

problem Challenges in causal discovery from observational data.
method Feature Matching Intervention (FMI) using matching to emulate perfect interventions.
result FMI outperforms in identifying causal features from observational data.

New method identifies latent variables without strong assumptions.

problem Recovering latent variables from observational data without strong assumptions.
method Diverse dictionary learning, using set-theoretic intersections, complements, and symmetric differences.
result Identifiability of latent variables up to appropriate indeterminacies without strong assumptions.

This paper establishes strong lower bounds for learning in revealing POMDPs.

problem Understanding the fundamental limits of reinforcement learning in revealing partially observable Markov Decision Processes (POMDPs).
method Develops strong PAC and regret lower bounds for learning in revealing POMDPs using multi-step revealing POMDPs as a case study.
result Strong polynomial lower bounds for learning in revealing POMDPs, achieving significantly smaller gaps against current upper bounds.

BERT fine-tuning is unstable due to optimization issues, not forgetting or dataset size.

problem Stability of fine-tuning BERT-based models across different random seeds.
method Analysis of BERT, RoBERTa, and ALBERT fine-tuned on GLUE datasets, identifying optimization difficulties as the cause of instability.
result Fine-tuning instability is due to optimization difficulties leading to vanishing gradients, not forgetting or dataset size.

New method combines experimental and observational data for causal inference.

problem Combining internal validity of experiments and larger sample sizes of observations.
method Empirical risk minimization (ERM) framework with cross-validation.
result Efficacy and reliability demonstrated on real and synthetic data.

Testing procedures for predictive regressions with lagged autoregressive variables imply a suboptimal inference in presence of small violations of ideal assumptions. We propose a novel testing framework resistant to such violations, which is consistent with nearly integrated regressors and applicable to multi-predictor…

2016-12-15abs ↗pdf ↗

Controlled interventions provide the most direct source of information for learning causal effects. In particular, a dose-response curve can be learned by varying the treatment level and observing the corresponding outcomes. However, interventions can be expensive and time-consuming. Observational data, where the treat…

2016-05-05abs ↗pdf ↗

The paper shows strong correlation between in-distribution and out-of-distribution performance in various machine learning models.

problem Understanding reliability of machine learning systems in unseen environments.
method Empirical analysis of various models and distribution shifts on CIFAR-10, ImageNet, and other datasets.
result Out-of-distribution performance is strongly correlated with in-distribution performance across different models and distribution shifts.

New method detects strong calibration in ML models, even for small poorly calibrated subgroups.

problem Auditing machine learning models for strong calibration is difficult, especially for small poorly calibrated subgroups.
method Reorder observations by expected residuals and use changepoint detection for score-based cumulative sum (CUSUM) test.
result The proposed adaptive CUSUM test consistently achieved higher power and more than doubled power in auditing mortality risk prediction models.

In this paper we characterize planar central configurations in terms of a sectional curvature value of the Jacobi-Maupertuis metric. This characterization works for the NN-body problem with general masses and any 1/rα1/r^α potential with α>0α> 0. We also observe dynamical consequences of these curvature values for relati…

2017-03-24abs ↗pdf ↗

New framework identifies strongly identifiable models from flexible generators.

problem Indeterminacies in generative models that prevent unique latent codes.
method Theoretical framework for analyzing latent variable models, excluding certain indeterminacies.
result Strong identifiability possible even with flexible nonlinear generators.