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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.

168,695 papers · 148 categories

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22436586 · Jun 202019922001200920172026
48 results for Dirichlet sums

Sharp bounds for Dirichlet sums lead to improved Bayesian algorithm analysis.

problem Improving Bayesian algorithm performance through precise deviation bounds.
method Novel integral representation of Dirichlet sum density, Gaussian approximation, complex analysis.
result Significantly sharpened regret bounds for Multinomial Thompson Sampling.

Bayesian models that mix multiple Dirichlet prior parameters, called Multi-Dirichlet priors (MD) in this paper, are gaining popularity. Inferring mixing weights and parameters of mixed prior distributions seems tricky, as sums over Dirichlet parameters complicate the joint distribution of model parameters. This paper s…

2017-08-17abs ↗pdf ↗

Estimates eigenvalues of poly-Laplace operator on lattice subgraphs.

problem Estimating eigenvalues of poly-Laplace operator on subgraphs of lattice graphs.
method Introduced discrete poly-Laplace operator, derived upper and lower bounds for eigenvalues.
result Poly-Laplace eigenvalues are at least squares of lower-order poly-Laplace eigenvalues.

We describe a simple and efficient procedure for approximating the Lévy measure of a Gamma(α,1)\text{Gamma}(α,1) random variable. We use this approximation to derive a finite sum-representation that converges almost surely to Ferguson's representation of the Dirichlet process based on arrivals of a homogeneous Poisson process.…

2011-07-04abs ↗pdf ↗

In this paper, the elastic Dirichlet-to-Neumann map ΞgΞ_g is studied for the stationary elasticity system in a compact Riemannian manifold (Ω,g)(Ω,g) with smooth boundary Ω\partial Ω. By overcoming methodological difficulties, we explicitly get matrix-valued full symbol for the elastic Dirichlet-to-Neumann map ΞgΞ_g. We …

2019-08-14abs ↗pdf ↗

Interior C2C^{2} estimates for sum Hessian quotient equations on Riemannian manifolds

problem Interior C2C^{2} estimates for sum Hessian quotient equations on Riemannian manifolds
method Interior C2C^{2} estimates for sum Hessian quotient equations on Riemannian manifolds
result Interior C2C^{2} estimates at the center of a geodesic ball

Motivated by a geometric problem, we introduce a new non-convex graph partitioning objective where the optimality criterion is given by the sum of the Dirichlet eigenvalues of the partition components. A relaxed formulation is identified and a novel rearrangement algorithm is proposed, which we show is strictly decreas…

2013-08-22abs ↗pdf ↗

The paper introduces a new model to correct bias in treatment effect estimates due to sample selection.

problem Bias in treatment effect estimates due to sample selection.
method Type 2 Tobit Bayesian Additive Regression Trees (TOBART-2) with Dirichlet Process Mixture distribution and soft trees.
result Corrects bias in treatment effect estimates by accounting for nonlinearities and model uncertainty.

It is proved that the Heisenberg group Nil3\operatorname*{Nil}\nolimits_{3} with a balanced metric, the sum of the left and right invariant metrics, splits as a Riemannian product T×Z\mathbb{T\times Z}, where T\mathbb{T} is a totally geodesic surface and Z\mathbb{Z} the center of Nil\operatorname*{Nil}% \nolimits_{3}. It…

2019-08-12abs ↗pdf ↗

A Dirichlet kk-partition of a domain URdU \subseteq \mathbb{R}^d is a collection of kk pairwise disjoint open subsets such that the sum of their first Laplace-Dirichlet eigenvalues is minimal. A discrete version of Dirichlet partitions has been posed on graphs with applications in data analysis. Both versions admit va…

2017-08-18abs ↗pdf ↗

Bayes-UCBVI tackles reinforcement learning with a new upper confidence bound method.

problem Optimizing exploration in reinforcement learning without bonuses.
method Bayes-UCBVI uses a quantile of a Q-value function posterior as an upper confidence bound.
result Proves a regret bound of order O~(H3SAT)\widetilde{O}(\sqrt{H^3SAT}) for tabular reinforcement learning.

New heat trace coefficients reveal curvature effects in polygonal domains.

problem Understanding heat trace behavior in polygonal domains with curved corners.
method Local heat trace expansion through order t1/2t^{1/2}, analyzing both Dirichlet and Neumann boundary conditions.
result Sharp sign law for the Dirichlet angular factor of the first corner-curvature heat invariant.

In this paper, we obtain a sharp upper bound for the sum of the first kk-th eigenvalues for this Dirichlet problem of poly-Laplacian with any order, which is viewed as an extension of the result due to Cheng and Wei (Journal of Differential Equations, 255 (2013), 220-233). In particular, if l=2l=2 and kk is large enou…

2013-07-19abs ↗pdf ↗

The existence of Dirichlet minimizing multiple-valued functions for given boundary data has been known since pioneering work of F. Almgren. Here we prove a multiple-valued analogue of the classical Plateau problem of the existence of area-minimizing mappings of the disk. Specifically, we find, for KN,K \in \mathbb N, $k…

2015-07-07abs ↗pdf ↗

The functional determinant of an elliptic operator with positive, discrete spectrum may be defined as eZ(0)e^{-Z'(0)}, where Z(s)Z(s), the zeta function, is the sum nλns\sum_n^{\infty} λ_n^{-s} analytically continued to ss around the origin. In this paper Z(0)Z'(0) is calculated for the Laplace operator with Dirichlet boundary…

1993-04-08abs ↗pdf ↗

The Special Lagrangian Potential Equation for a function uu on a domain ΩRnΩ\subset {\bf R}^n is given by tr{arctan(D2u)}=θ{\rm tr}\{\arctan(D^2 \,u) \} = θ for a contant θ(nπ2,nπ2)θ\in (-n {π\over 2}, n {π\over 2}). For C2C^2 solutions the graph of DuDu in Ω×RnΩ\times {\bf R}^n is a special Lagrangian submanfold. Much has been understood abou…

2020-01-27abs ↗pdf ↗

New methods for predicting compositional data using conformal prediction.

problem No well-established methods for constructing valid prediction sets in compositional data.
method Investigated three conformal prediction-based approaches for Dirichlet regression models.
result HDR approximation approach is robust in terms of coverage, while grid discretization reduces overcoverage.

In the first part of this article we obtain an identity relating the radial spectrum of rotationally invariant geodesic balls and an isoperimetric quotient 1/λirad=V(s)/S(s)ds\sum 1/λ_{i}^{\rm rad}=\int V(s)/S(s)ds. We also obtain upper and lower estimates for the series λi2(Ω)\sum λ_{i}^{-2}(Ω) where ΩΩ is an extrinsic ball of a proper m…

2016-05-14abs ↗pdf ↗

Adaptive Bayesian model for covariate-dependent power spectra analysis.

problem Estimating complex relationships and interactions between covariates and power spectra.
method Bayesian sum of trees model with local power spectrum estimation and reversible-jump MCMC for tree modifications.
result The method can accurately recover both smooth and abrupt changes in power spectra across multiple covariates.

Solves a specific Dirichlet problem on Hermitian manifolds.

problem Solving Dirichlet problem for Monge-Ampère type equations on Hermitian manifolds.
method Solves the Dirichlet problem for Monge-Ampère type equations for (n1)(n-1)-plurisubharmonic functions on Hermitian manifolds.
result Solves a specific Dirichlet problem on Hermitian manifolds.

Study non-linear Dirichlet-to-Neumann map for Poincaré-Einstein fillings.

problem Non-linear Dirichlet-to-Neumann map for Poincaré-Einstein fillings.
method Description of range in terms of Dirichlet-to-Neumann tensor, construction of hypersurface invariants.
result Unique conformally invariant Dirichlet-to-Neumann hypersurface invariants for Poincaré-Einstein fillings.

LDTA expands LDA's topic modeling capacity with tree-structured priors.

problem Limited expressiveness of Dirichlet priors in LDA for complex topic relationships.
method Introduces Latent Dirichlet-Tree Allocation (LDTA) with Dirichlet-Tree (DT) priors, and develops universal mean-field variational inference and Expectation Propagation.
result LDTA enables expressive, tree-structured priors over topic proportions, expanding modeling capacity of LDA.

Solves a specific Dirichlet problem on Riemannian manifolds.

problem Dirichlet problem for degenerate fully nonlinear elliptic equations on Riemannian manifolds.
method Derives existence of C1,1C^{1,1}-solutions under appropriate assumptions.
result Existence of C1,1C^{1,1}-solutions.

Study compares eigenvalues on spherically symmetric manifolds to Euclidean balls.

problem Comparing eigenvalues on spherically symmetric manifolds to Euclidean balls.
method Examines Dirichlet Laplace eigenvalues on balls of spherically symmetric manifolds and Euclidean space.
result Eigenvalues on spherically symmetric manifolds are smaller for small radii, but larger for hyperbolic spaces.

Enhances topic models to better handle polysemous words.

problem Lack of polysemy handling in Gaussian latent Dirichlet allocation.
method Introduces a hierarchical structure to capture polysemy in Gaussian latent Dirichlet allocation.
result Significantly improves polysemy detection and provides more parsimonious topic representations.

TPBS models improve robustness to overfitting with localized Dirichlet energy regularization.

problem Global Dirichlet energy-based regularization fails for TPBS models due to perfect interpolation.
method Propose local Dirichlet energy regularization and two inference estimators.
result TPBS models outperform neural networks in overfitting regimes and maintain competitive performance otherwise.

Graph Laplacians adapt to different manifold dimensions, while Dirichlet energies converge to a tensorized Dirichlet energy.

problem Understanding machine learning methods for data with varying intrinsic dimensions.
method Γ-convergence of graph Dirichlet energies and spectral convergence of graph Laplacians on intersecting manifolds of varying dimensions.
result Normalized Dirichlet energy converges to a tensorized Dirichlet energy that adapts to all dimensions simultaneously.

Discriminative classifier for compositional data using hierarchical mixture of Generalized Dirichlet models.

problem Classifying compositional data, especially in spam detection and color space identification.
method Hierarchical mixture of discriminative Generalized Dirichlet classifiers, using variational approximation for parameter learning.
result First time a variational upper-bound for Generalized Dirichlet mixture is proposed in literature.

The paper finds universal inequalities for eigenvalues on hyperbolic spaces.

problem Eigenvalues of the Dirichlet Laplacian on conformally flat Riemannian manifolds.
method Establishes universal inequalities for eigenvalues of the Dirichlet Laplacian on hyperbolic spaces.
result Establishes universal inequalities for eigenvalues of the Dirichlet Laplacian on hyperbolic spaces.

Geodesic balls with non-negative Ricci curvature have a sharp lower bound on their first Dirichlet eigenvalue.

problem Finding a sharp lower bound for the first Dirichlet eigenvalue of geodesic balls.
method Quantitative explicit inequality linking the width of geodesic balls to the spectral gap.
result A quantitative inequality relating the width of geodesic balls to the spectral gap between the first Dirichlet eigenvalue and its lower bound.

Paper solves Dirichlet problem for pp-convex hypersurfaces with curvature constraints.

problem Solving the Dirichlet problem for pp-convex hypersurfaces with prescribed curvature.
method Proved existence of a graphic hypersurface satisfying the prescribed curvature equation with homogeneous boundary condition, obtained an interior curvature estimate.
result Existence of a graphic hypersurface satisfying the prescribed curvature equation with homogeneous boundary condition.

Study gauge freedoms in elastic wave equations and Dirichlet-to-Neumann map.

problem Recover stiffness tensor and density from Dirichlet-to-Neumann map.
method Analyze invariance under coordinate transformations and gauge freedoms.
result Present gauge freedoms in the Dirichlet-to-Neumann map for Riemannian elastic wave equation.

A new method detects outliers using ensembles of Dirichlet process mixtures.

problem Challenges in unsupervised outlier detection using Dirichlet process mixtures.
method Ensembles of Dirichlet process Gaussian mixtures with random subspace and subsampling.
result Empirically outperforms existing approaches in unsupervised outlier detection.

Dirichlet pruning compresses neural networks by removing unimportant units.

problem Compressing large neural network models without sacrificing performance.
method Assigns Dirichlet distribution over network layers' units and uses variational inference to estimate parameters.
result Achieves state-of-the-art compression performance on larger architectures like VGG and ResNet.

We derive and approximate the conjugate prior of Dirichlet and beta distributions.

problem Intractability of conjugate prior for Dirichlet and beta distributions.
method Derive conjugate prior, define closed-form approximation, and provide algorithm.
result Closed-form approximation enables fully tractable Bayesian treatment.