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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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57113170226 · Jun 202019922001200920182026
48 results for definiteness issues

Paper introduces normalized flat minima to address scale dependence in neural network optimization.

problem Scale dependence in existing flat minima definitions affects generalization studies.
method PAC-Bayesian analysis to introduce normalized flat minima, free from scale dependence.
result Normalized flat minima provides better hierarchy in hypothesis class and improved generalization.

New definition resolves ambiguity in non-stationary bandit classification.

problem Ambiguity in classifying non-stationary bandits using existing definitions.
method Introducing a formal definition that resolves ambiguity and provides a unified approach.
result Unified approach applicable to both Bayesian and frequentist formulations, resolves classification issues.

This paper derives radial fields on manifolds of symmetric positive definite matrices.

problem Lack of an expression for radial fields on manifolds of symmetric positive definite matrices.
method Derives an expression for radial fields on manifolds of symmetric positive definite matrices.
result Derives an expression for radial fields on manifolds of symmetric positive definite matrices.

Improved Bayesian learning rule handles positive-definite constraints efficiently.

problem Bayesian learning rule struggles with positive-definite constraints.
method Proposes an improved rule using Riemannian gradient methods for block-coordinate natural parameterization.
result Outperforms existing methods without increased computation.

New definitions of conserved quantities at null infinity resolve ambiguities in general relativity.

problem Ambiguities in defining conserved quantities like angular momentum at null infinity.
method New definitions based on Chen-Wang-Yau quasilocal conserved quantities and optimal isometric embedding theory.
result These new definitions are free of supertranslation ambiguity and limit to classical Bondi mass.

Completes proof of index theorem using rigorous path integrals for supersymmetric quantum mechanics.

problem Analytic difficulties in generalizing Feynman's path integral to non-quadratic potentials.
method Develops rigorous path integrals for a class of Lagrangians including spinors on Riemannian manifolds.
result Steepest-descent approximation to path integral for twisted N=1/2N=1/2 supersymmetric quantum mechanics is provably correct.

We extend Sobolev transport to unbalanced measures on graphs.

problem Optimal transport struggles with measures of different total mass and high computational complexity.
method We propose a scalable unbalanced Sobolev transport (UST) for measures on graphs.
result UST admits a closed-form formula for fast computation and is negative definite.

Optimal transport for measures on noisy tree metrics is solved with robust approach.

problem Optimal transport problem for measures on noisy tree metrics.
method Max-min robust optimal transport approach considering uncertainty sets of tree metrics.
result Robust optimal transport admits a closed-form expression for fast computation.

New definitions of ESP for quantum reservoir computing handle non-stationary systems.

problem Traditional ESP does not apply to non-stationary systems.
method Introduce two new categories of ESP: non-stationary ESP and subset/subspace ESP.
result Demonstrates correspondence between non-stationary ESP and QRC with NARMA tasks.

New method estimates large covariance matrices using nonconvex penalties.

problem Estimating large covariance matrices in high-dimensional data.
method Developed a first-order algorithm using generalized nonconvex penalties.
result Positive-definite covariance estimators using nonconvex penalties.

Correlations between asset returns are important in many financial applications. In recent years, multivariate volatility models have been used to describe the time-varying feature of the correlations. However, the curse of dimensionality quickly becomes an issue as the number of correlations is k(k1)/2k(k-1)/2 for kk asse…

2007-02-27abs ↗pdf ↗

3D BF theory on certain 3-manifolds evaluated via residues and large k limits.

problem Singular and ill-defined partition function of 3D BF theory.
method Direct evaluation of path integral for specific 3-manifolds, using residues and large k limits of Chern-Simons matrix integrals.
result 3 definitions of the integral offer insights into the sum/integral over all flat connections.

Revises individual fairness by finding a fair metric for a model.

problem Difficulties in specifying a suitable fairness metric a priori.
method Introduces minimal metrics and applies randomized smoothing from adversarial robustness.
result Adapting minimal metrics to complex models yields interpretable fairness guarantees.

In this paper, we propose to (seamlessly) integrate b-bit minwise hashing with linear SVM to substantially improve the training (and testing) efficiency using much smaller memory, with essentially no loss of accuracy. Theoretically, we prove that the resemblance matrix, the minwise hashing matrix, and the b-bit minwise…

2011-05-23abs ↗pdf ↗

Paper defines the payback period for nonconventional cash flows using axioms.

problem Defining the payback period for nonconventional cash flows is challenging.
method Used axiomatic approach to define the payback period.
result The last break-even point of the project balance is the only definition consistent with axioms.

New measure of interference helps understand and mitigate learning issues in reinforcement learning.

problem Understanding and mitigating interference in reinforcement learning.
method Defined a new measure of interference, evaluated it, and identified key factors contributing to interference.
result Target network frequency and updates on the last layer are significant factors in interference.

Paper proposes a new algorithm for graph learning with covariance constraints.

problem Graphical models and factor analysis not jointly leveraged in graph learning processes.
method Penalized maximum likelihood estimation of an elliptical distribution with Riemannian optimization.
result Effectiveness of the proposed approach demonstrated on real-world data sets.

This post introduces model calibration and evaluation measures, highlighting issues with a common measure.

problem Ensuring model confidence accurately reflects true outcomes.
method Explains common calibration definition, ECE, and its drawbacks.
result New evaluation measures needed for comprehensive model calibration.

Paper proposes GEG to enhance fairness in binary and multi-class classification.

problem Fairness in multi-class classification tasks is under-explored.
method Formulates multi-objective problem between effectiveness and fairness constraints, proposes GEG algorithm.
result GEG improves fairness up to 92% and decreases accuracy up to 14%.

Fairness measures fail in predictive settings that intentionally shift outcomes.

problem Fairness measures fail in performative prediction settings.
method Formalized concept shift and counterfactual outcomes.
result Predictors that are fair during training become unfair during deployment.

We introduce a wrapped Gaussian for SPD matrices, enhancing data analysis.

problem Handling circular and non-flat data distributions on SPD manifolds.
method Introduced a non-isotropic wrapped Gaussian using the exponential map, derived theoretical properties, and proposed a maximum likelihood framework.
result Demonstrated the robustness and flexibility of the wrapped Gaussian model on synthetic and real-world datasets.

In this paper we propose an overview of the recent academic literature devoted to the applications of Hawkes processes in finance. Hawkes processes constitute a particular class of multivariate point processes that has become very popular in empirical high frequency finance this last decade. After a reminder of the mai…

2015-02-16abs ↗pdf ↗

Improved DLG extracts accurate labels from gradients, overcoming DLG's convergence issues.

problem Private training data leakage from shared gradients in distributed learning systems.
method Proposes iDLG, a simple approach to synthesize accurate labels from gradients.
result iDLG reliably extracts ground-truth labels from gradients, unlike DLG.

We define relative Ruan invariants that count embedded connected symplectic submanifolds which contact a fixed stable symplectic hypersurface V in a symplectic 4-manifold (X,w) at prescribed points with prescribed contact orders (in addition to insertions on X\V) for stable V. We obtain invariants of the deformation cl…

2009-12-03abs ↗pdf ↗

QUACKIE creates a new benchmark for NLP interpretability.

problem Evaluating NLP interpretability methods is challenging due to biased ground truths.
method Formulated a custom classification task from question-answering datasets, generating unbiased ground truths.
result Demonstrated the effectiveness of current interpretability methods on the new benchmark.

This paper addresses Gaussian Process regression over probability measures, revealing a non-stationarity issue between Euclidean and Wasserstein kernels.

problem Non-stationarity issue between Euclidean and Wasserstein kernels in Gaussian Process regression over probability measures.
method Assuming Euclidean input space, applying algebraic transformation based on uncovered non-stationarity relationship to create a non-stationary and Wasserstein-based Gaussian Process model.
result An algebraic transformation simplifies learning a non-stationary Gaussian Process model over probability measures.

The paper compares three hypoelliptic Laplacians on a specific 5D Cartan group.

problem Defining suitable hypoelliptic Laplacians for sharp estimates on Carnot groups.
method Introducing and comparing three hypoelliptic Laplacians on a specific Carnot group.
result Sharp div-curl type inequalities for the three hypoelliptic Laplacians.

META-DES.Oracle uses meta-learning and feature selection to improve ensemble selection accuracy.

problem Dynamic Ensemble Selection (DES) issues with classifier competence estimation.
method META-DES.Oracle integrates multiple criteria and an Oracle-based meta-feature selection scheme.
result META-DES.Oracle significantly improves classification accuracy compared to previous methods.

The clusters of a distribution are often defined by the connected components of a density level set. However, this definition depends on the user-specified level. We address this issue by proposing a simple, generic algorithm, which uses an almost arbitrary level set estimator to estimate the smallest level at which th…

2014-09-30abs ↗pdf ↗

New fairness concept extends minimax fairness to lexicographic fairness.

problem Fairness in supervised learning, especially lexicographic fairness.
method Introduced approximate lexifairness, derived algorithms for finding solutions, and proved generalization bounds.
result Proved that approximate lexifairness on training data implies approximate lexifairness on true distribution.

Positive definite operator-valued kernels generalize the well-known notion of reproducing kernels, and are naturally adapted to multi-output learning situations. This paper addresses the problem of learning a finite linear combination of infinite-dimensional operator-valued kernels which are suitable for extending func…

2012-03-07abs ↗pdf ↗