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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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166331497662 · Jun 202019922001200920172026
48 results for connectivity estimation

Study improves queue length estimation from connected vehicles by filtering parameters.

problem Large errors in estimated queue lengths at low market penetration rates.
method Used Kalman and Particle filters as multilevel real-time estimators.
result Filters reduce estimation errors and improve accuracy within 15 minutes.

Improved graph-based connectivity estimation using heat modelling.

problem Lack of explicit model-based, dynamic, multivariate, and directed connectivity estimation methods.
method Noise-driven heat modelling on graphs with relaxed assumptions and regularisation.
result Demonstrated ability to capture meaningful spatial structure across real-world datasets.

Method estimates network connectivity and dimensionality from multiple networks.

problem Estimating connectivity and dimensionality in samples of networks.
method Convex optimization with alternating direction method of multipliers.
result Method outperforms conventional methods in estimating connectivity and dimensionality.

In this paper, we develop connections between two seemingly disparate, but central, models in robust statistics: Huber's epsilon-contamination model and the heavy-tailed noise model. We provide conditions under which this connection provides near-statistically-optimal estimators. Building on this connection, we provide…

2019-07-01abs ↗pdf ↗

eDCF estimates intrinsic dimension using local connectivity.

problem Challenges in estimating intrinsic dimension due to scale dependence.
method eDCF: a novel, scalable, and parallelizable method based on Connectivity Factor (CF).
result eDCF consistently matches leading estimators with comparable MAE and higher exact intrinsic dimension match rates.

We show a connection between the Fourier spectrum of Boolean functions and the REINFORCE gradient estimator for binary latent variable models. We show that REINFORCE estimates (up to a factor) the degree-1 Fourier coefficients of a Boolean function. Using this connection we offer a new perspective on variance reduction…

2018-08-12abs ↗pdf ↗

New proof of injectivity for broken non-abelian X-ray transform in Minkowski space.

problem Injectivity of broken non-abelian X-ray transform in Minkowski space.
method Stability estimate considering gauge, light-sink connections, Bayesian inversion.
result Consistent recovery of light-sink connections from noisy data.

This expository article introduces the Kapustin-Witten equations to mathematicians. We discuss the connections between the Complex Yang-Mills equations and the Kapustin-Witten equations. In addition, we show the relation between the Kapustin-Witten equations, the moment map condition and the gradient Chern-Simons flow.…

2014-01-28abs ↗pdf ↗

This paper improves deep neural network approximation for fully connected networks, achieving optimal convergence rates.

problem Improving approximation of fully connected deep neural networks for optimal convergence rates.
method Deriving approximation bounds specifically for a narrower fully connected deep neural network.
result Achieves an optimal rate (up to a logarithmic factor) for fully connected deep neural networks.

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 ↗

In this paper, a frequency coefficient based on the Sen-Shorrocks-Thon (SST) poverty index notion is proposed. The clustering SST index can be used as the method for determination of the connection between similar neighbor sub-clusters. Consequently, connections can reveal existence of natural homogeneous. Through esti…

2017-10-19abs ↗pdf ↗

The paper explores quantum statistical manifolds and their autoparallelity, providing estimation-theoretical characterizations.

problem Quantum statistical manifolds and their geometric properties.
method Study of autoparallelity w.r.t. the e-connection, using quantum estimation theory.
result Characterizations of e-autoparallel submanifolds as statistical models with efficient estimators.

We prove a conformally invariant estimate for the index of Schrödinger operators acting on vector bundles over four-manifolds, related to the classical Cwikel-Lieb-Rozenblum estimate. Applied to Yang-Mills connections we obtain a bound for the index in terms of its energy which is conformally invariant, and captures th…

2019-01-14abs ↗pdf ↗

A linear non-Gaussian structural equation model called LiNGAM is an identifiable model for exploratory causal analysis. Previous methods estimate a causal ordering of variables and their connection strengths based on a single dataset. However, in many application domains, data are obtained under different conditions, t…

2011-04-28abs ↗pdf ↗

Optimistic estimate predicts best fitting performance of nonlinear models.

problem Evaluating the potential of nonlinear models in fitting.
method Proposes an optimistic estimate to quantify the smallest sample size for fitting nonlinear models.
result Predicts specific subsets of targets that can be fitted at overparameterization.

Improved method for numerical conformal mappings on complex domains.

problem Accurate and efficient computation of conformal mappings on multiply connected domains.
method Generalization and refinement of the conjugate function method using high-order finite element methods.
result Achieved accurate and efficient construction of boundary values for multiply connected domains.

SpINNEr uses matrix regression to analyze brain connectivity, improving accuracy over other methods.

problem Analyzing multi-dimensional data like brain imaging arrays using traditional scalar regression methods.
method SpINNEr applies matrix regression with nuclear norm and lasso norms to encourage low rank and sparse solutions.
result SpINNEr outperforms other methods in estimating brain connectivity, especially in well-connected regions.

Researchers found a quadratic estimate for embedding higher-dimensional simplices into sphere-connected sums.

problem Estimating the number of handles required for embedding higher-dimensional simplices into sphere-connected sums.
method Combining geometric topology, combinatorics, and linear algebra.
result Presented a quadratic estimate gckn2g \ge c_k n^2 for embedding kk-faces of nn-simplex.

Efficiently estimates neural connectivity using ensemble stimulation.

problem Estimating functional connectivity in large, behaving neural populations.
method Noisy group testing combined with convex optimization and Bayesian inference.
result Connectivity can be inferred with logarithmic growth in tests, even for large networks.

New estimates show all stable Einstein manifolds are linear stable with respect to Perelman's ν-entropy.

problem Estimating the smallest eigenvalue of Laplace-Beltrami operator for stable Einstein manifolds.
method Estimating the smallest positive eigenvalue λ1λ_1 of the Laplace-Beltrami operator for standard Einstein manifolds (G/H,gst)(G/H,g_{\operatorname{st}}) and proving λ1>2Eλ_1>2E for all but 7 exceptions.
result All stable Einstein manifolds found by Schwahn are linear stable with respect to Perelman's ν-entropy.

Estimates time-varying network connections using multi-stage smoothing.

problem Estimating edge probabilities of time-varying networks.
method Multi-stage smoothing: temporal local smoothing followed by node-domain smoothing.
result Captures both smooth temporal evolution and structural patterns in connectivity.

The concept of a conformal deformation has two natural extensions: quasiconformal and harmonic mappings. Both classes do not preserve the conformal type of the domain, however they cannot change it in an arbitrary way. Doubly connected domains are where one first observes nontrivial conformal invariants. Herbert Groetz…

2009-12-17abs ↗pdf ↗

A simple thresholding technique improves graph selection in neural connectivity studies.

problem Graphical model selection for functional neural connectivity in the presence of latent variables.
method Apply a hard thresholding operator to graphical Lasso, neighborhood selection, or CLIME estimators.
result Thresholded estimators outperform existing methods in graph selection consistency and empirical results.

Estimates neuronal connectivity from spike times using flexible Hawkes processes.

problem Learning latent network structure from multivariate point process data.
method Proposes a new nonstationary Hawkes process and uses sparse least squares estimation.
result Establishes non-asymptotic error bounds and selection consistency for estimated parameters.

A result (Corollary 4.3) in an article by Uhlenbeck (1985) asserts that the W1,pW^{1,p}-distance between the gauge-equivalence class of a connection AA and the moduli subspace of flat connections M(P)M(P) on a principal GG-bundle PP over a closed Riemannian manifold XX of dimension d2d\geq 2 is bounded by a constant ti…

2019-06-10abs ↗pdf ↗

Estimates parameters of interconnected linear systems using total variation penalization.

problem Joint estimation of parameters in interconnected linear dynamical systems.
method Total variation penalized least-squares estimator.
result The MSE goes to zero as the number of systems increases, even with constant trajectory length.

Proposes a method to cluster fMRI data and estimate brain connectivity networks.

problem Clustering fMRI data to identify patient groups based on brain connectivity.
method Random covariance clustering model (RCCM) to cluster subjects and estimate individual and shared FC networks.
result RCCM outperforms other methods in clustering and FC network estimation, demonstrated through simulations and real data.

We study the connections between spectral clustering and the problems of maximum margin clustering, and estimation of the components of level sets of a density function. Specifically, we obtain bounds on the eigenvectors of graph Laplacian matrices in terms of the between cluster separation, and within cluster connecti…

2018-12-16abs ↗pdf ↗

In this paper, we consider three typical problems on a locally finite connected graph. The first one is to study the Bochner formula for the Laplacian operator on a locally finite connected graph. We use the Bochner formula to derive the Bernstein type estimate of the heat equation. The second is to derive the Reilly t…

2013-04-01abs ↗pdf ↗

New method estimates neuronal connectivity from partially observed data.

problem Estimating neuronal connectivity from partially observed data.
method Two-step approach: low-rank covariance completion followed by graph structure estimation.
result Graph selection consistency demonstrated for one approach.

PULSE estimator improves prediction in causal inference with bounded interventions.

problem Optimizing causal models for bounded interventions.
method Relates K-class estimators to anchor regression, introduces PULSE estimator for minimization of mean squared prediction error with bounded constraints.
result PULSE estimator outperforms other estimators in real data and simulation experiments, especially in weak instrument settings.

Deep neural networks estimate regression functions on manifolds.

problem Estimating regression functions on manifolds from data.
method Fully connected deep neural networks with ReLU activation, analyzing convergence rates.
result Estimates achieve a rate of convergence dependent on manifold dimension, not predictor dimension.

In this paper we prove a new matrix Li-Yau-Hamilton estimate for Kähler-Ricci flow. The form of this new Li-Yau-Hamilton estimate is obtained by the interpolation consideration originated in \cite{Ch1}. This new inequality is shown to be connected with Perelman's entropy formula through a family of differential equalit…

2005-02-23abs ↗pdf ↗

New framework for dense weighted networks with community-specific patterns.

problem Dense networks with varying edge weights across communities.
method Proposes a new model with functions mapping node characteristics to edge weights, requiring few parameters.
result Developed a bootstrap methodology for generating new networks.

In this article, we analyze the SPICE method developed in [1], and establish its connections with other standard sparse estimation methods such as the Lasso and the LAD-Lasso. This result positions SPICE as a computationally efficient technique for the calculation of Lasso-type estimators. Conversely, this connection i…

2012-09-21abs ↗pdf ↗

The paper defines surface area for graphs and derives spectral estimates.

problem Understanding connectivity measures and spectral properties of graphs.
method Introducing surface area concepts related to inverse degree and deriving spectral bounds.
result An upper bound on the second eigenvalue for planar graphs.

Study pseudoholomorphic maps using canonical connection.

problem Characterize pseudoholomorphic maps between almost Hermitian manifolds.
method Use canonical connection and Bochner formulas to derive estimates and theorems.
result Obtained C2C^2-estimate of canonical second fundamental form and Liouville type theorems.