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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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4693139185 · Jun 202019922001200920172026
48 results for transit clusters

We define transit clusters to simplify causal diagrams and preserve their essential properties.

problem Clustering variables in causal diagrams can alter essential properties of causal effects.
method We define transit clusters and provide an algorithm to find them, ensuring they preserve causal effect identifiability.
result Transit clusters simplify causal effect identification and maintain their essential properties.

We present a global optimization algorithm for clustering data given the ratio of likelihoods that each pair of data points is in the same cluster or in different clusters. To define a clustering solution in terms of pairwise relationships, a necessary and sufficient condition is that belonging to the same cluster sati…

2015-06-09abs ↗pdf ↗

The interaction between transitivity and sparsity, two common features in empirical networks, implies that there are local regions of large sparse networks that are dense. We call this the blessing of transitivity and it has consequences for both modeling and inference. Extant research suggests that statistical inferen…

2013-07-08abs ↗pdf ↗

There have been several spectral bounds for the percolation transition in networks, using spectrum of matrices associated with the network such as the adjacency matrix and the non-backtracking matrix. However they are far from being tight when the network is sparse and displays clustering or transitivity, which is repr…

2017-10-04abs ↗pdf ↗

Multilayer graphs are commonly used for representing different relations between entities and handling heterogeneous data processing tasks. New challenges arise in multilayer graph clustering for assigning clusters to a common multilayer node set and for combining information from each layer. This paper presents a theo…

2016-09-23abs ↗pdf ↗

Geometric framework links clustering accuracy to structural recovery.

problem Understanding the trade-off between robustness and sensitivity in clustering.
method Develops a clustering condition number to compare within-cluster scale to the minimum loss increase required to move a point across a cluster boundary.
result Sharp phase transitions for exact recovery under different objectives, providing geometric principle for interpreting low objective values.

Proposes ConiVAT for better cluster assessment and clustering with background knowledge.

problem Challenges in cluster assessment and clustering with noise and bridge points.
method Uses background constraints to improve VAT/iVAT for complex datasets.
result Improves clustering accuracy and resolves issues with noise and bridge points.

SC-InfoNCE improves InfoNCE for feature clustering in contrastive learning.

problem Lack of theoretical understanding of InfoNCE's feature clustering mechanism.
method Introduced a transition probability matrix to model data augmentation dynamics and optimize feature similarity.
result SC-InfoNCE achieves strong performance across diverse domains, aligning feature similarity with downstream data.

Solves complex clustering and rotation synchronization problem.

problem Challenges in classifying and synchronizing rotated objects into multiple categories.
method Semidefinite programming relaxations to solve the joint problem of community detection and synchronization.
result Exact recovery of community detection and synchronization when extending stochastic block model.

Develops a new tensor model for clustering with degree correction.

problem Clustering with unknown degree heterogeneity in multiway data.
method Degree-corrected tensor block model with estimation guarantees.
result Demonstrates an intrinsic statistical-to-computational gap for tensors of order three or greater.

New method clusters directed and undirected graphs without losing directional information.

problem Clustering directed graphs due to asymmetry in edge connectivity.
method Generalized Dirichlet Energy (GDE) and generalized spectral clustering (GSC).
result GSC outperforms existing methods in clustering accuracy and robustness.

New insights show stochastic initialization prevents token clustering in deep Transformers.

problem Understanding token dynamics in deep stochastic Transformers.
method Analysis of deep Transformers with random initialization noise, proving convergence to an interacting-particle system on the sphere.
result Initialization noise prevents token clustering, leading to antipodal formations.

Paper proposes an alternative to anchor points for learning with noisy labels.

problem Learning with noisy labels is challenging due to inaccurate labels.
method Estimates transition matrix using clusterability condition and noisy labels.
result Estimation of transition matrix is more accurate and efficient than anchor points.

Adaptive orthogonalization of data for clustering and visualization.

problem Clustering and visualization of data with high specificity.
method Adaptive orthogonalization process using Gromov-Wasserstein feedback.
result Method refines orthogonality of data to achieve high specificity clustering.

We generalise surface cluster algebras to the case of infinite surfaces where the surface contains finitely many accumulation points of boundary marked points. To connect different triangulations of an infinite surface, we consider infinite mutation sequences. We show transitivity of infinite mutation sequences on tria…

2017-04-06abs ↗pdf ↗

We use a cluster ensemble to determine the number of clusters, k, in a group of data. A consensus similarity matrix is formed from the ensemble using multiple algorithms and several values for k. A random walk is induced on the graph defined by the consensus matrix and the eigenvalues of the associated transition proba…

2014-08-05abs ↗pdf ↗

Consider a two-class clustering problem where we observe Xi=iμ+ZiX_i = \ell_i μ+ Z_i, ZiiidN(0,Ip)Z_i \stackrel{iid}{\sim} N(0, I_p), 1in1 \leq i \leq n. The feature vector μRpμ\in R^p is unknown but is presumably sparse. The class labels i{1,1}\ell_i\in\{-1, 1\} are also unknown and the main interest is to estimate them. We are interested …

2015-02-24abs ↗pdf ↗

Unsupervised learning is a discipline of machine learning which aims at discovering patterns in big data sets or classifying the data into several categories without being trained explicitly. We show that unsupervised learning techniques can be readily used to identify phases and phases transitions of many body systems…

2016-06-01abs ↗pdf ↗

Characterizes optimal reconstruction error in high-dimensional Gaussian mixtures.

problem Optimizing reconstruction error in high-dimensional sparse Gaussian mixtures.
method Exact asymptotic characterization using state evolution of AMP algorithm.
result Identification of statistical-to-computational gap between AMP and information-theoretic threshold.

The article detects market regimes from covariance matrices using VLSTAR and clustering models.

problem Market regime switching is hard to detect due to time-varying correlation coefficients.
method The article applies VLSTAR and unsupervised hierarchical clustering on monthly realized covariance matrices.
result VLSTAR outperforms clustering in detecting market regimes.

Diffusion maps help learn complex quantum phase transitions from data.

problem Learning quantum phase transitions from experimental data is challenging.
method Diffusion maps for nonlinear dimensionality reduction and spectral clustering.
result Diffusion maps can learn complex phase transitions unsupervised.

This work improved clustering methods by analyzing various datasets and dendrograms.

problem Avoiding false positives in clustering, especially for unimodal and bimodal data.
method Applied agglomerative clustering methods (single, average, median, complete, centroid, Ward's) to various datasets.
result Many methods detected two clusters in unimodal data, with single-linkage being more resilient.

Machine learning predicts critical points for directed percolation models.

problem Determining critical points for directed percolation models.
method Supervised and unsupervised machine learning algorithms (CNN and DBSCAN) were used.
result Machine learning accurately predicts critical points for both models.

This article explores and analyzes the unsupervised clustering of large partially observed graphs. We propose a scalable and provable randomized framework for clustering graphs generated from the stochastic block model. The clustering is first applied to a sub-matrix of the graph's adjacency matrix associated with a re…

2018-05-25abs ↗pdf ↗

Study quantifies performance gap between tensor and matrix-based approaches in nested matrix-tensor model.

problem Estimating a planted signal in a nested matrix-tensor model.
method Comparing tensor-based and matrix-based approaches for best rank-one approximation of tensor data.
result Derives precise algorithmic threshold for the unfolding approach and shows BBP-type transition behavior.

As a model problem for clustering, we consider the densest k-disjoint-clique problem of partitioning a weighted complete graph into k disjoint subgraphs such that the sum of the densities of these subgraphs is maximized. We establish that such subgraphs can be recovered from the solution of a particular semidefinite re…

2016-03-16abs ↗pdf ↗

Nowadays, data are generated massively and rapidly from scientific fields as bioinformatics, neuroscience and astronomy to business and engineering fields. Cluster analysis, as one of the major data analysis tools, is therefore more significant than ever. We propose in this work an effective Semi-supervised Divisive Cl…

2014-12-24abs ↗pdf ↗

Linear dynamical systems are a fundamental and powerful parametric model class. However, identifying the parameters of a linear dynamical system is a venerable task, permitting provably efficient solutions only in special cases. This work shows that the eigenspectrum of unknown linear dynamics can be identified without…

2019-08-02abs ↗pdf ↗