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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.

169,341 papers · 148 categories

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8.3%16.7%25.0%33.3% · Jan 199319922001200920182026
48 results for relative density

Meta-learning improves relative density-ratio estimation from limited data.

problem Estimating relative density-ratios from few instances.
method Meta-learning using neural networks to extract and embed dataset information for relative DRE.
result Meta-learning enables efficient and effective adaptation to few instances for relative DRE.

Divergence estimators based on direct approximation of density-ratios without going through separate approximation of numerator and denominator densities have been successfully applied to machine learning tasks that involve distribution comparison such as outlier detection, transfer learning, and two-sample homogeneity…

2011-06-23abs ↗pdf ↗

Researchers classify invariant operators on weighted densities.

problem Classifying invariant differential operators on weighted densities.
method Investigated the aff(n1)\mathfrak{aff}(n|1)-module structure and invariant binary differential operators.
result Computed the first aff(n1)\mathfrak{aff}(n|1)-relative differential cohomology.

REGS samples from unnormalized distributions using gradient flow and neural networks.

problem Sampling from unnormalized distributions with high accuracy and efficiency.
method REGS is a particle method that iteratively transforms samples from a reference distribution to match an unnormalized target distribution using Wasserstein gradient flow and neural networks.
result REGS outperforms state-of-the-art methods in sampling from challenging multimodal distributions and real datasets.

Stable and consistent model alignment for language models without assuming human preference models.

problem Lack of statistical consistency in existing alignment methods.
method Relative density ratio optimization between preferred and mixture of preferred and non-preferred data distributions.
result Our approach achieves statistical consistency and stability, providing tighter convergence guarantees.

The quotient of normal variables has power-law decay, applied to asset price tails.

problem Understanding the distribution of relative price changes in finance.
method Analyzing the quotient of normal distributions and deriving power-law decay densities.
result Relative price changes follow a power-law distribution with density f(x)f0x2f(x) \simeq f_0 x^{-2}.

The study finds dense orbits and absolute period leaves for complex flows.

problem Existence of dense orbits for real Rel flows on holomorphic 1-forms.
method Established a density criterion for mSL(2,R){ m SL}(2,\mathbb{R})-orbit closures, verified using explicit constructions.
result Found dense leaves and examples of absolute period foliation.

Proves well-posedness for Einstein equations with specific boundary conditions.

problem Well-posedness of vacuum Einstein equations with twisted Dirichlet boundary conditions.
method Proves local-in-time well-posedness for the IBVP of the Einstein equations with specified conformal class and scalar densities.
result Proves well-posedness for the Einstein equations with twisted Dirichlet boundary conditions.

The equity risk premium is derived from SPX option chains using a model-light approach.

problem Estimating the equity risk premium from option data.
method Model-light approach using Gaussian mixture models and exponential tilting.
result The equity risk premium is calculated from the real-world probability densities inferred from option quotes.

The paper explores recovery thresholds in heterogeneous SBM with varying community sizes and densities.

problem Understanding the limits of community recovery in heterogeneous SBM.
method Generalized Stochastic Block Model with varying community sizes and densities.
result Exact recovery of very small communities is possible under certain conditions.

Conditional density estimation generalizes regression by modeling a full density f(yjx) rather than only the expected value E(yjx). This is important for many tasks, including handling multi-modality and generating prediction intervals. Though fundamental and widely applicable, nonparametric conditional density estimat…

2012-06-20abs ↗pdf ↗

New method estimates density-derivative-ratios directly for clustering and ridge estimation.

problem Accurately estimating ratios of density derivatives.
method Direct estimation of density-derivative-ratios without density estimation.
result Developed methods significantly outperform existing techniques, especially for high-dimensional data.

Paper develops estimators for unbounded density ratios with applications in error control.

problem Estimating density ratios with unbounded domains and ranges.
method Least squares and logistic regression loss functions for density ratio estimation.
result Established upper bounds on estimation errors with optimal rates for unbounded density ratios.

Paper tackles unbounded density ratio estimation for covariate shift adaptation.

problem Understudied challenge in statistical learning: unbounded density ratios.
method Three-step estimation method: relative density ratio, truncation, and transformation.
result Established rigorous convergence guarantees for density ratio and regression estimators.

In stochastic portfolio theory, a relative arbitrage is an equity portfolio which is guaranteed to outperform a benchmark portfolio over a finite horizon. When the market is diverse and sufficiently volatile, and the benchmark is the market or a buy-and-hold portfolio, functionally generated portfolios introduced by Fe…

2014-07-31abs ↗pdf ↗

We investigate the position of the Buchen-Kelly density in a family of entropy maximising densities which all match European call option prices for a given maturity observed in the market. Using the Legendre transform which links the entropy function and the cumulant generating function, we show that it is both the uni…

2011-02-01abs ↗pdf ↗

Kernel density estimation (KDE) is a popular statistical technique for estimating the underlying density distribution with minimal assumptions. Although they can be shown to achieve asymptotic estimation optimality for any input distribution, cross-validating for an optimal parameter requires significant computation do…

2011-02-14abs ↗pdf ↗

A model-free framework extracts risk-neutral densities from short-dated options.

problem Arbitrage and bid-ask spread issues in short-dated options.
method Develops ARIES for filtering static arbitrage and SEDEx for density extraction.
result Robust density extraction across various market conditions and volatility smiles construction.

Study online monotone density estimation with expert aggregation and log-optimal calibration.

problem Online monotone density estimation and log-optimal calibration.
method Proposed two online estimators: Grenander estimator and expert aggregation estimator.
result Online estimators achieve O(n1/3)O(n^{1/3}) cumulative log-likelihood gap and nlogn\sqrt{n\log{n}} pathwise regret bound.

LGKDE learns graph density using neural networks and perturbations.

problem Graph density estimation challenges in capturing structural patterns and semantic variations.
method LGKDE uses graph neural networks to represent graphs as discrete distributions and learns graph metrics via maximum mean discrepancy.
result LGKDE outperforms state-of-the-art baselines in graph anomaly detection.

Proposes a method for approximating transition densities of SDEs driven by gamma processes.

problem Calculating transition densities for SDEs driven by gamma processes.
method Taylor-type approximation and conditional expectation of multiple stochastic integrals.
result Efficiency of the proposed method demonstrated through numerical tests.

Felix visualizes cosmic filaments using topology.

problem Visualizing cosmic filaments in the complex cosmic web.
method Representing filaments as ascending manifold geometry in Morse-Smale complex, generating a hierarchy and querying for filaments based on density ranges.
result Felix efficiently extracts and visualizes cosmic filaments, including those in void-like regions.

The paper establishes minimax bounds for estimating low-rank quantum density matrices.

problem Estimating low-rank quantum density matrices with optimal error rates.
method Developed minimax lower bounds and upper bounds for least squares estimator with von Neumann entropy penalization.
result Sharp upper and lower bounds for various distances (Kullback-Leibler, Hellinger, Schatten p-norm) are attained.

We study graph estimation and density estimation in high dimensions, using a family of density estimators based on forest structured undirected graphical models. For density estimation, we do not assume the true distribution corresponds to a forest; rather, we form kernel density estimates of the bivariate and univaria…

2010-01-10abs ↗pdf ↗

The paper develops a theory of conformal density at infinity for groups with contracting elements.

problem Understanding conformal dynamics at infinity for groups with contracting elements.
method Introducing a class of convergence boundary and establishing the basic theory of conformal density on it.
result Unified theory of conformal density on various boundaries for different types of groups.

Study finds optimal martingale coupling between two distributions with minimal entropy.

problem Finding the optimal martingale coupling between two distributions with minimal relative entropy.
method Solving a dual problem to find the log-density of the optimal coupling, which represents the marginal and martingale constraints.
result The log-density of the optimal coupling is given by a triplet of real functions representing the marginal and martingale constraints.

Deep density methods improve filtering in high-dimensional systems.

problem Nonlinear filtering in high-dimensional systems.
method Two deep density methods based on Feynman-Kac formulas and neural networks.
result Logarithmic deep backward stochastic differential equation filter outperforms classical methods in high dimensions.

We formulate and analyze an inverse problem using derivatives prices to obtain an implied filtering density on volatility's hidden state. Stochastic volatility is the unobserved state in a hidden Markov model (HMM) and can be tracked using Bayesian filtering. However, derivative data can be considered as conditional ex…

2012-03-29abs ↗pdf ↗

EagleEye detects localized density anomalies in multivariate data.

problem Identifying signal events, regime changes, or model mismatch in scientific data.
method EagleEye pinpoints local over- and under-densities by assigning anomaly scores based on binary membership sequences and binomial null models.
result EagleEye can detect genuine local anomalies and estimate background purity.