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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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138276414552 · Jun 202019922001200920172026
48 results for linear $k$-means

The paper examines conditions for linearity in a conditional mean estimator under vector Poisson noise.

problem Conditions for linearity of the conditional mean estimator in vector Poisson noise.
method Analyzes prior distributions and their impact on the conditional mean estimator's linearity.
result The only prior distribution that induces linearity is a product gamma distribution, and non-zero dark current parameter prevents linearity.

New results on financial equilibria in markets with general semimartingales.

problem Existence and uniqueness of mean-variance equilibria in semimartingale markets.
method Analysis of dynamic mean-variance hedging and fixed-point problems.
result First results allowing for general semimartingales and both discrete and continuous time.

Near-optimal algorithms for mean estimation and linear regression with Gaussian covariates and Huber contamination.

problem Gaussian mean estimation and linear regression with Gaussian covariates in the presence of Huber contamination.
method Near-optimal algorithms with optimal error guarantees, achieving sample complexity n=ildeO(d/ε2)n = ilde{O}(d/ε^2) and almost linear runtime.
result First sample near-optimal and almost linear-time algorithms with optimal error guarantees for both problems.

The MEM method uses data-driven priors for linear inverse problems, proving convergence and estimating differences.

problem Linear inverse problems with approximate priors.
method Maximum Entropy on the Mean (MEM) method with data-driven priors.
result Empirical mean convergence and estimates for prior differences based on epigraphical distance.

Study policy gradient for large-agent mean-field control and game in continuous time.

problem Optimal policy learning for large number of agents in continuous-time mean-field systems.
method Policy gradient method applied to linear-quadratic mean-field control and game models.
result Policy gradient converges to optimal solution at a linear rate for both mean-field control and game.

This work extends Ledoit-Wolf shrinkage to unknown mean covariance estimation.

problem Large dimensional covariance matrix estimation with unknown mean under Kolmogorov asymptotics.
method Extending Ledoit-Wolf linear shrinkage to translation-invariant estimators, proving their convergence properties.
result A new estimator outperforms other standard estimators empirically.

This work shows linear convergence for two-layer neural networks in mean-field regime.

problem Optimizing two-layer neural networks in the mean-field regime.
method Mean-field analysis and continuous-time noisy gradient descent.
result Establishes linear convergence rate for two-layer neural networks.

Paper proves linear convergence of SCMS algorithm for directional data.

problem Identifying density ridges in directional data.
method Generalized SCMS algorithm to directional data, derived from SCGA with adaptive step size.
result Linear convergence of the proposed directional SCMS algorithm.

Paper establishes sufficient condition for comparing linear combinations of infinite-mean risks.

problem Comparing linear combinations of infinite-mean risks under stochastic dominance.
method Introduced a new class of distributions and used majorization order to compare weights.
result Linear combinations of random variables are stochastically larger when their weight vectors are smaller in majorization order.

Analyzes multi-day stock returns, showing linear volatility and mean dependence.

problem Linear dependence of volatility and mean in accumulated stock returns.
method Modified Jones-Faddy skew t-distribution analysis.
result Linear dependence of volatility and mean on the number of days of accumulation.

Double Q-learning has the same mean-squared error as Q-learning under certain conditions.

problem Comparing the mean-squared error of Double Q-learning and Q-learning.
method Theoretical analysis based on Lyapunov equations for both tabular and linear function approximation settings.
result The asymptotic mean-squared error of Double Q-learning is exactly equal to that of Q-learning under specific conditions.

Kernel clustering algorithm improved for large datasets using incomplete Cholesky factorization.

problem Large memory usage in kernel-based clustering for large-scale datasets.
method Approximate the kernel matrix using incomplete Cholesky factorization and apply linear kk-means clustering.
result The proposed method achieves similar performance to kernel kk-means clustering but handles large-scale datasets efficiently.

In order to model entanglements of polymers in a confined region, we consider the linking numbers and writhes of cycles in random linear embeddings of complete graphs in a cube. Our main results are that for a random linear embedding of KnK_n in a cube, the mean sum of squared linking numbers and the mean sum of square…

2015-08-05abs ↗pdf ↗

Improved disability insurance model with collective health claims.

problem Enhance disability insurance model with collective health claims.
method Expand classic semi-Markov model with collective health claims, solve many-body problem using mean-field approach.
result Mean-field approach simplifies complex model into a transparent pricing method.

Our aim is to study invariant hypersurfaces immersed in the Euclidean space Rn+1\mathbb{R}^{n+1}, whose mean curvature is given as a linear function in the unit sphere Sn\mathbb{S}^n depending on its Gauss map. These hypersurfaces are closely related with the theory of manifolds with density, since their weighted mean cu…

2019-08-20abs ↗pdf ↗

Diffusion means converge to extrinsic means for long times on spheres.

problem Understanding the long-time behavior of diffusion means on manifolds.
method Introduced diffusion means as a parameterized family of location statistics on manifolds, and analyzed their convergence to extrinsic means for long times.
result For real projective spaces and connected compact symmetric spaces, the long-time limit of diffusion means is conjectured to be the extrinsic mean in the isometric embedding.

This paper achieves optimal regret bounds for locally private linear contextual bandit.

problem Designing locally private linear contextual bandit algorithms with optimal regret bounds.
method New algorithmic and analytical ideas, including mean absolute deviation analysis and layered principal component regression.
result Achieves an ildeO(T) ilde O(\sqrt{T}) regret upper bound for locally private linear contextual bandit.

New findings allow infinite mean intensity Hawkes processes to be stable.

problem Stability condition for Hawkes processes with infinite mean intensity.
method Analysis of Quadratic Hawkes processes with infinite mean intensity.
result Quadratic Hawkes processes are always stationary with infinite mean intensity when total endogeneity ratio exceeds unity.

Unified framework for shrinkage, thresholding, and regularization in normal mean estimation and linear regression.

problem Estimation of normal mean in multivariate settings with correlated observations.
method Approximate risk minimization over a functional class of shrinkage-thresholding rules.
result Unified estimator NOMAD for shrinkage, thresholding, and regularization.

Kernel means are frequently used to represent probability distributions in machine learning problems. In particular, the well known kernel density estimator and the kernel mean embedding both have the form of a kernel mean. Unfortunately, kernel means are faced with scalability issues. A single point evaluation of the …

2015-03-01abs ↗pdf ↗

Novel approach to Nash equilibrium in mean-field stochastic games with operator resolvents.

problem Finding Nash equilibrium in mean-field stochastic games with mean-field interaction.
method Proposed a novel approach to derive Nash equilibrium semi-explicitly using operator resolvents and stochastic Fredholm equations.
result Equilibrium of the NN-player game converges to mean-field equilibrium, and ε\varepsilon-Nash equilibrium derived as a by-product.

The paper introduces a non-linear version of the process convolution formalism for building covariance functions for multi-output Gaussian processes. The non-linearity is introduced via Volterra series, one series per each output. We provide closed-form expressions for the mean function and the covariance function of t…

2018-10-10abs ↗pdf ↗

Efficient algorithms for kk-means clustering frequently converge to suboptimal partitions, and given a partition, it is difficult to detect kk-means optimality. In this paper, we develop an a posteriori certifier of approximate optimality for kk-means clustering. The certifier is a sub-linear Monte Carlo algorithm b…

2017-10-03abs ↗pdf ↗

The paper explores rigidity of hypersurfaces with constant shifted curvature functions in hyperbolic space.

problem Rigidity of hypersurfaces with constant shifted curvature functions in hyperbolic space.
method Characterizations and rigidity investigations for hypersurfaces with constant weighted shifted mean curvatures or ratios.
result Rigidity results for hypersurfaces with constant linear combinations of weighted shifted mean curvatures and radially symmetric shifted mean curvatures.

GBMixed boosts mixed models for clustered data, estimating mean and variance flexibly.

problem Flexible estimation of mean and variance components in clustered data.
method Gradient Boosting framework for linear mixed models with likelihood-based gradients.
result GBMixed accurately recovers complex nonlinear fixed effects and covariances.

Neural networks improve geospatial data analysis by relaxing linearity assumptions.

problem Traditional geospatial analysis assumes linear models, limiting flexibility.
method Embedding neural networks within traditional geostatistical models for non-linear mean functions.
result NN-GLS algorithm provides consistent and scalable predictions for irregular spatial data.

New method for high-dimensional linear regression using empirical Bayes.

problem Estimating prior in high-dimensional linear regression.
method Variational empirical Bayes approach with NPMLE and mean field approximation.
result Established asymptotic consistency and computational efficiency of the method.

Study on PG learning for LQ MFC problems with common noise, proving convergence and sample complexity.

problem Optimal policy learning in LQ MFC problems with common noise and entropy regularization.
method Comprehensive error analysis of PG algorithms in both model-based and model-free settings.
result Global linear convergence and sample complexity of PG algorithms in model-free setting.

Developed LQ MFG theory with common noise, proving existence and uniqueness.

problem Linear-quadratic mean field games with common noise.
method Coupled forward-backward stochastic evolution equations (FBSEEs) in Hilbert spaces.
result Existence and uniqueness of solutions for small and arbitrary finite time horizons.

We propose a novel adaptive test of goodness-of-fit, with computational cost linear in the number of samples. We learn the test features that best indicate the differences between observed samples and a reference model, by minimizing the false negative rate. These features are constructed via Stein's method, meaning th…

2017-05-22abs ↗pdf ↗

New numerical method for non-linear asset price model with CEV volatility.

problem Describing stochastic volatility in asset price dynamics.
method Proposes a mean-reverting theta-rho model with CEV volatility, constructs a truncated EM method.
result Truncated EM solutions can evaluate path-dependent financial products.