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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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83167250333 · Jun 202019922001200920172026
48 results for misspecified systems

Framework predicts responses in misspecified systems using GPLFM and BNNs.

problem Predicting responses in dynamical systems with model misspecification.
method Integrates GPLFM and BNNs for uncertainty-aware inference and prediction.
result Systematic propagation of uncertainty from diagnosis to prediction.

Reward hacking exploits misspecified rewards, affecting agent capabilities and true performance.

problem Reward hacking in RL models exploiting reward misspecifications.
method Constructed four RL environments with misspecified rewards; analyzed agent capabilities and behavior.
result More capable agents exploit reward misspecifications, achieving higher proxy reward but lower true reward.

Nonparametric modeling approaches show very promising results in the area of system identification and control. A naturally provided model confidence is highly relevant for system-theoretical considerations to provide guarantees for application scenarios. Gaussian process regression represents one approach which provid…

2018-11-16abs ↗pdf ↗

Paper proposes methods to reduce bias and variance in recommender systems.

problem Bias in recommender systems due to users' preferences.
method Proposes a principled approach to reduce bias and variance in DR methods, and a novel semi-parametric collaborative learning approach.
result The proposed methods outperform existing debiasing methods in both theory and experiments.

The paper examines when importance weighting is needed for nonparametric and misspecified models.

problem When is importance weighting correction needed for covariate shift adaptation?
method Analysis of IW-corrected kernel ridge regression in various settings.
result The importance weighting correction is needed for nonparametric and misspecified models to obtain the best approximation of the true unknown function.

The paper examines Gaussian process means under misspecified likelihoods and smoothness.

problem Accuracy of Gaussian process approximations under misspecified smoothness and likelihood.
method Analysis of Gaussian process properties under misspecified conditions.
result The accuracy of Gaussian process approximations is influenced by experimental design and kernel choice.

New PG losses improve decision optimization in misspecified models.

problem Improving decision optimization in models that are not perfectly specified.
method Introducing Perturbation Gradient (PG) losses to connect decision loss with directional derivatives and optimizing using gradient techniques.
result PG losses yield best-in-class policies asymptotically, even in misspecified settings.

Framework corrects model form errors in structural dynamics predictions.

problem Model form errors in parametric models of structural dynamics.
method Gaussian Process Latent Force Model (GPLFM) for non-parametric discrepancy representation, linear Bayesian filtering for state and discrepancy estimation, modal reduction for computational tractability.
result Significant reduction of displacement and rotation prediction errors under unseen excitations.

New methods for CI testing under model misspecification.

problem Challenges in CI testing with misspecified models.
method Proposes new approximations and upper bounds for testing errors of regression-based CI tests.
result Introduces the Rao-Blackwellized Predictor Test (RBPT) robust against misspecified inductive biases.

This paper examines how investors mislearn factor risk premia under structural breaks in a misspecified Bayesian framework.

problem Investors' mislearning of factor risk premia under structural breaks in asset pricing models.
method Proposes a minimal Bayesian framework to study how investors learn under a misspecified model that underestimates structural breaks.
result Elevated mislearning is associated with stronger long-horizon returns and Sharpe ratios, consistent with an equilibrium premium for acute model uncertainty.

Study on sequential prediction with log-loss, focusing on well-specified and misspecified cases.

problem Sequential prediction with log-loss under different specification conditions.
method Analysis of cumulative regret in well-specified and misspecified cases for a Gaussian location hypothesis class.
result Cumulative regrets in well-specified and misspecified cases asymptotically coincide for the dd-dimensional Gaussian location hypothesis class.

Study non-asymptotic bounds for robust estimators under misspecified models.

problem Evaluate performance of robust estimators under adversarial conditions.
method Propose a general approach to adversarial risk analysis, including investigations on generalization and approximation errors.
result Establish non-asymptotic upper bounds for adversarial excess risk under Lipschitz loss functions.

Suppose an investor aims at Delta hedging a European contingent claim h(S(T))h(S(T)) in a jump-diffusion model, but incorrectly specifies the stock price's volatility and jump sensitivity, so that any hedging strategy is calculated under a misspecified model. When does the erroneously computed strategy super-replicate the t…

2019-10-20abs ↗pdf ↗

Improved algorithm for misspecified MLMDPs with bounded regret and space/time complexities.

problem Misspecified linear Markov decision processes.
method Proposes an algorithm with three desirable properties: bounded regret, bounded space/time complexities, and no need for misspecification input.
result Regret scales as Kmax{εextmis,εexttol}K \max \{ \varepsilon_{ ext{mis}}, \varepsilon_{ ext{tol}} \}, improving existing bounds.

New method improves GP uncertainty quantification for misspecified priors.

problem Uncertainty quantification for GPs under incorrect priors.
method Constructs a confidence sequence using martingale techniques.
result Empirically outperforms standard GP methods in robustness and utility for Bayesian Optimization.

The paper tackles long-context linear system identification with improved sample complexity bounds.

problem Identifying dynamical systems with long dependencies over fixed context windows.
method Established sample complexity bounds for systems with linear dependencies over a context window of length p.
result The learning process is not hindered by slow mixing properties in extended context windows.

Self-consistency improves the accuracy of model comparison methods.

problem Improving the accuracy of model comparison methods when simulation models are misspecified.
method Supplement traditional simulation-based training with a self-consistency loss on unlabeled real data.
result Self-consistency training improves model comparison accuracy, especially in open-world scenarios.

Bayesian algorithms perform well even with misspecified priors, especially in meta-learning.

problem Performance degradation of Bayesian algorithms with misspecified priors.
method Thompson sampling and meta-learning analysis with misspecified priors.
result Thompson sampling's performance degrades gracefully with misspecification, with a bound of ildeO(H2ε) ilde{\mathcal{O}}(H^2 ε).

New algorithms for optimizing functions with noisy feedback, even when the model is misspecified.

problem Optimizing a black-box function with noisy bandit feedback, especially when the model is misspecified.
method Developed two algorithms based on Gaussian process methods: EC-GP-UCB and Phased GP Uncertainty Sampling.
result Achieved optimal dependence on misspecification error without prior knowledge, and effective in stochastic contextual settings.

Paper analyzes spectral algorithms under covariate shift, providing convergence rates.

problem Addressing distributional mismatch in regression models.
method Incorporates importance weights into spectral algorithms in RKHS.
result Establishes minimax-optimal convergence rates for misspecified cases.

Existing nonconvex statistical optimization theory and methods crucially rely on the correct specification of the underlying "true" statistical models. To address this issue, we take a first step towards taming model misspecification by studying the high-dimensional sparse phase retrieval problem with misspecified link…

2017-12-18abs ↗pdf ↗

New algorithms for best arm identification in bandits robust to misspecified parameters.

problem Inconsistent learning performance of traditional MAB algorithms when parameters are misspecified.
method Proposes two classes of asymptotically near-optimal algorithms for statistically robust MAB under fixed-budget pure exploration.
result Establishes fundamental performance limits and proposes algorithms that are asymptotically near-optimal.

There is vast empirical evidence that given a set of assumptions on the real-world dynamics of an asset, the European options on this asset are not efficiently priced in options markets, giving rise to arbitrage opportunities. We study these opportunities in a generic stochastic volatility model and exhibit the strateg…

2010-02-26abs ↗pdf ↗

The paper tackles joint learning of linear systems, improving accuracy with pooled data.

problem Estimating transition matrices of multiple related linear systems more accurately.
method Developed novel techniques to bound estimation errors and establish high probability bounds for singular values.
result Significant gains in accuracy achieved by pooling data across systems.

New method improves uncertainty quantification for large batch sizes and misspecified models.

problem Challenges in tuning algorithms for accurate uncertainty quantification in large batch sizes and misspecified models.
method Proposes new discrete-time approximations to SGD and SGLD, proving error bounds for practical tuning.
result Quantitative, non-asymptotic error bounds for accurate predictions of covariance and autocorrelation time.

RoPE framework calibrates misspecified simulators for reliable inference.

problem Misspecification compromises reliability of simulation-based inference.
method Data-driven calibration using optimal transport and a small calibration set.
result RoPE framework improves inference accuracy and uncertainty calibration.

Sharp bounds on ATE with unmeasured confounders, valid even when misspecified.

problem Bounding average treatment effects with unmeasured confounders.
method Distributionally robust optimization, double sharpness, double validity.
result Proposes estimators with robustness properties for valid bounds.

Bayesian metalearning improves performance in linear bandits with misspecified priors.

problem Improper priors lead to suboptimal performance in sequential decision-making.
method Proves performance bounds for metalearning priors in stochastic linear bandits and develops a metalearning algorithm.
result Metalearning can improve performance by learning the prior from multiple tasks.

Paper develops a method to predict spatial point processes with guarantees.

problem Predicting the number of events in space with uncertainty.
method Regularized method to learn spatial models with out-of-sample guarantees.
result Method provides valid prediction intervals even when model is misspecified.

A new method improves efficiency in finding optimal personalized treatment rules.

problem Heteroscedasticity and misspecified treatment-free effect models affect optimal ITR estimation.
method E-Learning framework that accounts for covariate-treatment dependent variance of residuals.
result E-Learning framework improves efficiency of optimal ITR estimation.

A fast method estimates correlations in hybrid systems using observable market data.

problem Estimating instantaneous correlations in hybrid systems from observable data.
method Empirical correlations between observable market quantities are used to estimate state variables' correlations. Linear systems are involved, and the matrix is converted to positive semidefinite if necessary.
result The estimates are reasonably accurate, especially with more than 1,000 data points.

ACE improves GBI for simulators by approximating cost functions, making inference more efficient.

problem Inference for misspecified simulators is overly restrictive.
method Amortized cost estimation (ACE) for Generalized Bayesian Inference (GBI).
result ACE provides accurate cost predictions and more efficient inference.

Study optimizes learning rates for conditional mean embedding estimates.

problem Consistency of kernel ridge regression for conditional mean embedding.
method Adaptive statistical learning rate derived for misspecified setting.
result Upper bound matches optimal O(logn/n)O(\log n / n) rates without assuming finite dimensionality.

Paper presents a machine learning method to improve significance tests for misspecified linear models.

problem Misspecification of linear assumptions in social science models leads to inaccurate significance levels.
method Apply machine learning to fit ground truth function, calculate linear approximation, and adjust the estimator.
result The method significantly outperforms linear regression for non-linear ground truth functions.

Proposes a method to improve SBI under model misspecification.

problem Unreliable inference from SBI methods under model misspecification.
method Introduces a regularized loss function to penalize statistics that increase model-data mismatch.
result Demonstrates superior performance and robust inference in misspecified scenarios.

Study phase retrieval under misspecified models using generative priors.

problem Estimating signals from phase measurements with model misspecification.
method Two-step approach: spectral initialization followed by iterative refinement.
result Statistical rate of order (klogL)(logm)/m\sqrt{(k\log L)\cdot (\log m)/m} under suitable conditions.

Statsformer validates and adapts LLM-derived semantic priors for improved supervised learning.

problem Unreliable semantic priors from LLMs can degrade supervised learning performance.
method Adapts LLM-derived feature scores into a family of learner-specific prior-injection mechanisms, calibrating their influence using out-of-fold validation.
result Improves prediction performance by adaptively downweighting unreliable LLM priors, ensuring a guardrailed statistical learning system.