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.
Paper proposes a new method for sparse covariance Cholesky factor estimation.
This paper develops a fast algorithm for solving nonlinear PDEs using sparse Cholesky factorization.
A new method learns DAGs from Gaussian data without verifying acyclicity.
A new method for efficient causal structure learning at scale.
Method regularizes Cholesky factors to detect nonstationarity in longitudinal data.
The modified Cholesky decomposition is commonly used for precision matrix estimation given a specified order of random variables. However, the order of variables is often not available or cannot be pre-determined. In this work, we propose to address the variable order issue in the modified Cholesky decomposition for sp…
We consider multi-task regression models where observations are assumed to be a linear combination of several latent node and weight functions, all drawn from Gaussian process (GP) priors that allow nonzero covariance between grouped latent functions. We show that when these grouped functions are conditionally independ…
A new method for efficient Gaussian process inference using sparse approximations.
Paper proposes a fast algorithm to recover causal DAGs with latent variables.
Improved aircraft structure prediction using derivative-enhanced sparse Cholesky GP method.
New SPD metrics improve stability and efficiency in neural networks.
Kernel-based clustering algorithm can identify and capture the non-linear structure in datasets, and thereby it can achieve better performance than linear clustering. However, computing and storing the entire kernel matrix occupy so large memory that it is difficult for kernel-based clustering to deal with large-scale …
The paper explores Cholesky decompositions for symmetric matrices and their geometric properties.
Bayesian networks are a class of popular graphical models that encode causal and conditional independence relations among variables by directed acyclic graphs (DAGs). We propose a novel structure learning method, annealing on regularized Cholesky score (ARCS), to search over topological sorts, or permutations of nodes,…
RPCholesky approximates kernel matrices with few evaluations.
In this paper, we present a general, multistage framework for graphical model approximation using a cascade of models such as trees. In particular, we look at the problem of covariance matrix approximation for Gaussian distributions as linear transformations of tree models. This is a new way to decompose the covariance…
The sparse inverse covariance estimation problem is commonly solved using an -regularized Gaussian maximum likelihood estimator known as "graphical lasso", but its computational cost becomes prohibitive for large data sets. A recent line of results showed--under mild assumptions--that the graphical lasso esti…
This paper proposes the recursive and square-root BLS algorithms to improve the original BLS for new added inputs, which utilize the inverse and inverse Cholesky factor of the Hermitian matrix in the ridge inverse, respectively, to update the ridge solution. The recursive BLS updates the inverse by the matrix inversion…
We propose an algorithmic framework for convex minimization problems of a composite function with two terms: a self-concordant function and a possibly nonsmooth regularization term. Our method is a new proximal Newton algorithm that features a local quadratic convergence rate. As a specific instance of our framework, w…
We consider the problem of learning a Gaussian variational approximation to the posterior distribution for a high-dimensional parameter, where we impose sparsity in the precision matrix to reflect appropriate conditional independence structure in the model. Incorporating sparsity in the precision matrix allows the Gaus…
New algorithm extends Greville's method for partitioned matrices efficiently and stably.
Efficiently discovers causal DAG permutations without additional assumptions.
We demonstrate an equivalence between reproducing kernel Hilbert space (RKHS) embeddings of conditional distributions and vector-valued regressors. This connection introduces a natural regularized loss function which the RKHS embeddings minimise, providing an intuitive understanding of the embeddings and a justificatio…
Conjugate gradient methods improve efficiency for high-dimensional GLMMs.
We present a new Riemannian metric, termed Log-Cholesky metric, on the manifold of symmetric positive definite (SPD) matrices via Cholesky decomposition. We first construct a Lie group structure and a bi-invariant metric on Cholesky space, the collection of lower triangular matrices whose diagonal elements are all posi…
New heuristic selects fewer assets for efficient portfolios, reducing costs.
New quadrature method using randomly pivoted Cholesky outperforms existing techniques.
The original Broad Learning System (BLS) on new added nodes and its existing efficient implementation both assume the ridge parameter lambda -> 0 in the ridge inverse to approximate the generalized inverse, and compute the generalized inverse solution for the output weights. In this paper, we propose two ridge solution…
New method differentiates square-root Kalman filters robustly.
Scalable algorithm for sampling Gaussian processes using sparse grids and preconditioners.
New Krylov subspace methods speed up mixed-effects models with crossed random effects.
A scalable algorithm for GP regression selects relevant covariates efficiently.
New method for geodesics of multivariate normals, derived from a Toda lattice.
Accelerated RPCholesky speeds up kernel matrix approximations.
New method trains sparse Gaussian processes without matrix inversion.
Develops a fast algorithm for fitting multilevel factor models.
Spike and Slab priors have been of much recent interest in signal processing as a means of inducing sparsity in Bayesian inference. Applications domains that benefit from the use of these priors include sparse recovery, regression and classification. It is well-known that solving for the sparse coefficient vector to ma…
New method for hyperparameter tuning in sparse matrix factorization.
Solving systems of linear equations is a problem occuring frequently in water engineering applications. Usually the size of the problem is too large to be solved via direct factorization. One can resort to iterative approaches, in particular the conjugate gradients method if the matrix is symmetric positive definite. P…
Sparse APCA identifies sparse factors in financial returns over time.
In many applications, data come with a natural ordering. This ordering can often induce local dependence among nearby variables. However, in complex data, the width of this dependence may vary, making simple assumptions such as a constant neighborhood size unrealistic. We propose a framework for learning this local dep…
Most machine learning methods require careful selection of hyper-parameters in order to train a high performing model with good generalization abilities. Hence, several automatic selection algorithms have been introduced to overcome tedious manual (try and error) tuning of these parameters. Due to its very high sample …
Proposes FARM model combining latent factor and sparse regression.
We observe that gradients computed via the reparameterization trick are in direct correspondence with solutions of the transport equation in the formalism of optimal transport. We use this perspective to compute (approximate) pathwise gradients for probability distributions not directly amenable to the reparameterizati…
Deep weight factorization improves neural network training through smooth optimization of sparse penalties.
Sparse VAE learns latent factors from high-dimensional data.
Bayesian model infers factor dimensionality and sparse loading matrix adaptively.
Sparse GFA identifies disease factors in FTD subgroups.