Research
On-device research index

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.

169,051 papers · 148 categories

Trend · papers per month

25.0%50.0%75.0%100.0% · Sep 199219922001200920172026
48 results for matrix elements

New methods combine matrix elements and machine learning for more accurate LHC measurements.

problem High-dimensional data and complex detector response make likelihood function estimation difficult.
method Review and application of traditional histogram, Matrix Element Method, Optimal Observables, and neural density estimation techniques. Use of MadMiner for automation.
result New techniques have the potential to substantially improve LHC measurement sensitivity.

Many tasks require finding groups of elements in a matrix of numbers, symbols or class likelihoods. One approach is to use efficient bi- or tri-linear factorization techniques including PCA, ICA, sparse matrix factorization and plaid analysis. These techniques are not appropriate when addition and multiplication of mat…

2012-06-27abs ↗pdf ↗

This paper improves matrix completion by leveraging element importance and non-uniform sampling.

problem The challenge of completing low-rank matrices from noisy, subsampled measurements.
method Employing leverage scores to characterize element importance and devising a biased sampling procedure.
result Theoretical and empirical evidence shows that a smaller number of entries (about O(nrlog2(n))O(nr\log^2(n))) can recover a low-rank matrix with noise.

In this paper we form relations for the determination of the elements of the Eötvös matrix of the Earth's normal gravity field. In addition a relation between the Gauss curvature of the normal equipotential surface and the Gauss curvature of the actual equipotential surface both passing through the point P is presented…

2011-07-11abs ↗pdf ↗

Origin-destination (OD) matrices are often used in urban planning, where a city is partitioned into regions and an element (i, j) in an OD matrix records the cost (e.g., travel time, fuel consumption, or travel speed) from region i to region j. In this paper, we partition a day into multiple intervals, e.g., 96 15-min …

2018-11-13abs ↗pdf ↗

A new method uses SPDEs to efficiently model random fields on complex domains.

problem Efficient representation of random fields on complex domains for engineering and machine learning.
method Uses SPDEs to develop a scalable framework for statFEM and GP regression.
result Can model anisotropic, non-stationary random fields with arbitrary smoothness.

For any matrix A in R^(m x n) of rank ρ, we present a probability distribution over the entries of A (the element-wise leverage scores of equation (2)) that reveals the most influential entries in the matrix. From a theoretical perspective, we prove that sampling at most s = O ((m + n) ρ^2 ln (m + n)) entries of the ma…

2013-10-14abs ↗pdf ↗

Matrix completion, i.e., the exact and provable recovery of a low-rank matrix from a small subset of its elements, is currently only known to be possible if the matrix satisfies a restrictive structural constraint---known as {\em incoherence}---on its row and column spaces. In these cases, the subset of elements is sam…

2013-06-12abs ↗pdf ↗

This paper concerns cluster algebras with principal coefficients A(S,M) associated to bordered surfaces (S,M), and is a companion to a concurrent work of the authors with Schiffler [MSW2]. Given any (generalized) arc or loop in the surface -- with or without self-intersections -- we associate an element of (the fractio…

2011-08-17abs ↗pdf ↗

In this paper we give a new basis, ΛΛ, for the Homflypt skein module of the solid torus, S(ST)\mathcal{S}({\rm ST}), which was predicted by Jozef Przytycki, using topological interpretation. The basis ΛΛ is different from the basis ΛΛ^{\prime}, discovered independently by Hoste--Kidwell \cite{HK} and Turaev \cite{Tu} w…

2014-12-11abs ↗pdf ↗

Predict missing movie ratings or graph embeddings with low rank matrices.

problem Predicting missing entries in a ratings matrix or graph embeddings with known linear relations.
method Low rank matrix completion approach applied to graph embeddings.
result Effective methods for predicting missing entries in matrices and graph embeddings.

BlockEcho method improves imputation of block-wise missing data.

problem Block-wise missing data reduces interpolation capability and predictive power.
method Integrates Matrix Factorization (MF) within Generative Adversarial Networks (GAN) to retain long-distance inter-element relationships.
result Superior performance on public datasets across three domains, especially at higher missing rates.

Paper derives matrix formulae and proves skein relations for non-orientable surfaces in quasi-cluster algebras.

problem Understanding quasi-cluster algebras on non-orientable surfaces.
method Developed matrix formulae and proved skein relations for quasi-cluster variables.
result Laurent expansion and skein relations for quasi-cluster variables on non-orientable surfaces.

The Drinfeld double of a finite dimensional Hopf algebra is a quasi-triangular Hopf algebra with the canonical element as the universal RR-matrix, and one can obtain a ribbon Hopf algebra by adding the ribbon element. The universal quantum invariant of framed links is constructed using a ribbon Hopf algebra. In that c…

2016-12-25abs ↗pdf ↗

Suppose, we are given a set of nn elements to be clustered into kk (unknown) clusters, and an oracle/expert labeler that can interactively answer pair-wise queries of the form, "do two elements uu and vv belong to the same cluster?". The goal is to recover the optimum clustering by asking the minimum number of quer…

2017-06-23abs ↗pdf ↗

The paper analyzes how Gaussian kernel parameters affect posterior covariance in Gaussian processes.

problem Understanding the influence of Gaussian kernel parameters on posterior covariance in Gaussian processes.
method Geometric analysis and a posteriori error estimation techniques from adaptive finite element methods.
result The bandwidth parameter and spatial distribution of observations significantly influence posterior covariance and its matrix.

Proposes a method to identify elements in a skewness matrix for multivariate skew-elliptical distributions.

problem Label switching issue in Bayesian estimation of skewness matrix.
method Imposes a positive lower-triangular constraint and uses Bayesian sparse estimation with horseshoe prior.
result Successfully estimates the true structure of skewness dependency.

Modified Newton step for online learning reduces matrix size for large datasets.

problem Handling large multi-class datasets efficiently in online learning.
method Element-wise multiplication to reduce matrix size of second order matrices.
result Proposed method achieves similar mistake rates to popular methods but with faster computations.

Quantum theory uses modular group representations to assign invariants to 3-manifolds.

problem Assigning invariants to 3-manifolds via modular group representations.
method Projective representations of the modular group derived from a noncommutative torus.
result Computed traces and determinants of matrices associated with modular group elements.

As a typical dimensionality reduction technique, random projection can be simply implemented with linear projection, while maintaining the pairwise distances of high-dimensional data with high probability. Considering this technique is mainly exploited for the task of classification, this paper is developed to study th…

2013-12-12abs ↗pdf ↗

We know that any element A of the group SO(3) can be represented as A = A1 A2 A1', where A1, A1' are elements of SO1(2)={A is an element of SO(3) | Ae1=e1}, and SO2(2)={A is an element of SO(3) | Ae2=e2} . This fact is known as Euler's angle. When this situation, a matrix A is called the generator. In the present paper…

2010-10-28abs ↗pdf ↗

We study how well one can recover sparse principal components of a data matrix using a sketch formed from a few of its elements. We show that for a wide class of optimization problems, if the sketch is close (in the spectral norm) to the original data matrix, then one can recover a near optimal solution to the optimiza…

2015-03-12abs ↗pdf ↗

Most recent results in matrix completion assume that the matrix under consideration is low-rank or that the columns are in a union of low-rank subspaces. In real-world settings, however, the linear structure underlying these models is distorted by a (typically unknown) nonlinear transformation. This paper addresses the…

2015-12-29abs ↗pdf ↗

Matrix formulas for super Teichmüller spaces generalize previous work and yield super λ-lengths.

problem Calculating super λ-lengths on bordered surfaces with marked points.
method Using holonomy matrices of elements in the supergroup OSp(1|2) to compute super λ-lengths in decorated super Teichmüller spaces.
result Matrix formulas for arcs on bordered surfaces yield super λ-lengths in Penner-Zeitlin's decorated super Teichmüller space.

This paper develops a Bayesian procedure for estimation and forecasting of the volatility of multivariate time series. The foundation of this work is the matrix-variate dynamic linear model, for the volatility of which we adopt a multiplicative stochastic evolution, using Wishart and singular multivariate beta distribu…

2008-02-01abs ↗pdf ↗

Given nn i.i.d. observations of a random vector (X,Z)(X,Z), where XX is a high-dimensional vector and ZZ is a low-dimensional index variable, we study the problem of estimating the conditional inverse covariance matrix Ω(z)=(E[(XE[XZ])(XE[XZ])TZ=z])1Ω(z) = (E[(X-E[X \mid Z])(X-E[X \mid Z])^T \mid Z=z])^{-1} under the assumption that the set of non…

2014-12-24abs ↗pdf ↗

This paper considers a restriction to non-negative matrix factorization in which at least one matrix factor is stochastic. That is, the elements of the matrix factors are non-negative and the columns of one matrix factor sum to 1. This restriction includes topic models, a popular method for analyzing unstructured data.…

2016-09-19abs ↗pdf ↗

Linear dimensionality reduction techniques are powerful tools for image analysis as they allow the identification of important features in a data set. In particular, nonnegative matrix factorization (NMF) has become very popular as it is able to extract sparse, localized and easily interpretable features by imposing an…

2015-05-26abs ↗pdf ↗