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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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56112168224 · May 202619922001200920172026
48 results for exact recovery threshold

Sharp threshold for exact recovery in non-uniform hypergraph stochastic block model.

problem Community detection in random hypergraphs with non-uniform hyperedge probabilities.
method Sharp threshold established; two efficient algorithms for exact recovery.
result Sharp threshold for exact recovery; information-theoretic lower bound on misclassification.

We study graph matching with correlated Gaussian features and find thresholds for exact recovery.

problem Graph matching with correlated Gaussian features.
method Information-theoretic thresholds and conditions for exact and almost exact recovery.
result Contextual information introduces a richer structure, with thresholds for exact and almost exact recovery no longer coinciding.

We determine the information-theoretic cutoff value on separation of cluster centers for exact recovery of cluster labels in a KK-component Gaussian mixture model with equal cluster sizes. Moreover, we show that a semidefinite programming (SDP) relaxation of the KK-means clustering method achieves such sharp threshol…

2020-01-05abs ↗pdf ↗

Exact recovery method for community detection in Gaussian mixtures with dependent noise.

problem Community detection in Gaussian mixtures with dependent and heterogeneous noise.
method Maximum likelihood estimator (MLE) for constrained quadratic optimization problem, using ΣΣ-whitened separation and local inequalities.
result Sharp exact-recovery threshold and no-gap mechanism in the unknown-size setting.

New algorithm achieves almost exact graph matching in almost quadratic time.

problem Graph matching under correlated Erdős-Rényi models.
method Rank-based graph matching using local tree correlation tests.
result Achieves almost exact recovery in almost quadratic time complexity.

The stochastic block model (SBM) is a random graph model with different group of vertices connecting differently. It is widely employed as a canonical model to study clustering and community detection, and provides a fertile ground to study the information-theoretic and computational tradeoffs that arise in combinatori…

2017-03-29abs ↗pdf ↗

Paper uses SDP for community detection with side information.

problem Community detection in graphs with additional non-graph data.
method Formulates SDP relaxation for maximum likelihood node labeling with side information.
result SDP achieves same exact recovery threshold as maximum likelihood with side information.

This paper sets thresholds for recovering vertex correspondences in partially correlated graphs.

problem Recovering hidden vertex correspondences in partially correlated graphs.
method Proposed partially correlated Erdős-Rényi graphs model; information-theoretic thresholds; correlated functional digraphs.
result Optimal rates for partial and exact recovery of vertex correspondences.

Study exact community detection in k-community Gaussian mixtures with different intensities.

problem Community detection in k-community Gaussian mixtures with varying intensities.
method Explicitly find the threshold for exact recovery of maximum likelihood estimation.
result Threshold for exact recovery of maximum likelihood estimation is identified.

This paper tackles exact recovery of clusters in a stochastic Ising model on a SBM graph.

problem Recovering clusters in a stochastic Ising model on a SBM graph.
method Proposes a Stochastic Ising Block Model (SIBM) and establishes a sharp threshold for exact recovery.
result Sharp threshold mm^\ast for exact recovery of clusters in SIBM, with O(n)O(n) time complexity for mmm \ge m^\ast.

Paper models graph edge dependencies using latent variables for community detection.

problem Graphs' edge dependencies not fully explained by community membership.
method Introduces auxiliary latent variables to model edge dependencies and analyzes conditions for exact recovery.
result Exact recovery possible by semidefinite programming down to maximum likelihood threshold.

The binary symmetric stochastic block model deals with a random graph of nn vertices partitioned into two equal-sized clusters, such that each pair of vertices is connected independently with probability pp within clusters and qq across clusters. In the asymptotic regime of p=alogn/np=a \log n/n and q=blogn/nq=b \log n/n for fixe…

2014-11-24abs ↗pdf ↗

Simultaneous orthogonal matching pursuit (SOMP) and block OMP (BOMP) are two widely used techniques for sparse support recovery in multiple measurement vector (MMV) and block sparse (BS) models respectively. For optimal performance, both SOMP and BOMP require \textit{a priori} knowledge of signal sparsity or noise vari…

2019-12-18abs ↗pdf ↗

Motivated by applications such as discovering strong ties in social networks and assembling genome subsequences in biology, we study the problem of recovering a hidden 2k2k-nearest neighbor (NN) graph in an nn-vertex complete graph, whose edge weights are independent and distributed according to PnP_n for edges in the…

2019-11-18abs ↗pdf ↗

Study optimal spectral estimator for semi-supervised node classification.

problem Semi-supervised node classification on CSBM with limited labels.
method Spectral estimator inspired by PCA, graph ridge regression, GCN.
result Achieves information-theoretical threshold for exact recovery.

Recovery of low-rank matrices from a small number of linear measurements is now well-known to be possible under various model assumptions on the measurements. Such results demonstrate robustness and are backed with provable theoretical guarantees. However, extensions to tensor recovery have only recently began to be st…

2019-08-22abs ↗pdf ↗

We study the effect of the quality and quantity of side information on the recovery of a hidden community of size K=o(n)K=o(n) in a graph of size nn. Side information for each node in the graph is modeled by a random vector with the following features: either the dimension of the vector is allowed to vary with nn, while …

2018-09-05abs ↗pdf ↗

Study spectral properties of sparse random graphs to recover latent vectors.

problem Recovering latent vectors in sparse random geometric graphs.
method Analyzes spectral concentration and uses orthogonal polynomial expansions, decoupling, and matrix concentration.
result Sharpens spectral norm bounds and proves exact recovery for Gaussian mixture models.

Bottom-up algorithms outperform top-down in hierarchical community detection at intermediate levels.

problem Finding the optimal hierarchical community structure in networks.
method A bottom-up algorithm for hierarchical clustering of networks.
result Bottom-up algorithms achieve the information-theoretic threshold for exact recovery at intermediate levels of the hierarchy.

SGD recovers multiple signal vectors in noisy tensor PCA.

problem Estimating multiple signal vectors from noisy tensor observations.
method Online stochastic gradient descent (SGD) in high dimensions with detailed analysis of correlations.
result Sequential elimination of correlations allows recovery of all spikes from Np2N^{p-2} samples.

Study of Langevin dynamics for tensor PCA recovery in high dimensions.

problem Recovering hidden signal vectors (spikes) from noisy Gaussian tensor observations.
method Langevin dynamics approach for nonconvex optimization.
result Sample complexity matches the single-spike case but degrades for all spikes.

Statistical-computational gap found in aligning multiple Gaussian graphs.

problem Aligning multiple Gaussian graphs with unknown signals.
method Generalized informational threshold and computational barrier analysis.
result Existence of a statistical-computational gap in multiple Gaussian graph alignment.

Matrix multiplication is a fundamental building block for large scale computations arising in various applications, including machine learning. There has been significant recent interest in using coding to speed up distributed matrix multiplication, that are robust to stragglers (i.e., machines that may perform slower …

2019-05-16abs ↗pdf ↗

New findings on community recovery in SBM with many communities.

problem Determining community recovery conditions in SBM with more than sqrt(n) communities.
method Constructing motifs and counting them to prove community recovery above the proposed threshold.
result Proving community recovery above the proposed threshold in SBM with K >= sqrt(n) communities.

ReLU networks learn simple models even with many parameters, overcoming traditional wisdom.

problem Generalization of overparameterized neural networks.
method Convex optimization and sparse recovery perspective applied to two-layer ReLU networks with standard weight decay.
result ReLU networks learn simple models that explain the data, analogous to sparse recovery in compressed sensing.

Unified framework for pattern recovery in penalized and thresholded estimation.

problem Pattern recovery in penalized and thresholded estimation methods.
method Defining a novel pattern notion based on subdifferentials, introducing accessibility and noiseless recovery conditions.
result Unified and extended conditions for pattern recovery in a broad class of penalized estimators.

Paper explores exact recovery of communities in weighted graphs using Gaussian and exponential distributions.

problem Exact recovery of communities in weighted graphs with Gaussian and exponential distributions.
method Introduces a new semi-metric to describe conditions for exact recovery and analyzes conditions for both complete and incomplete graphs.
result Necessary and sufficient conditions for exact recovery are asymptotically tight and applicable to both complete and incomplete graphs.

In this paper, we propose a general framework for sparse and low-rank tensor estimation from cubic sketchings. A two-stage non-convex implementation is developed based on sparse tensor decomposition and thresholded gradient descent, which ensures exact recovery in the noiseless case and stable recovery in the noisy cas…

2018-01-29abs ↗pdf ↗

Guarantees sparse recovery for neural networks with iterative hard thresholding.

problem Recovering sparse network weights in neural networks.
method Structural properties of sparse network weights and iterative hard thresholding algorithm.
result Simple iterative hard thresholding algorithm recovers sparse network weights exactly using linear memory.

New findings support a new community recovery threshold for Stochastic Block Model with many communities.

problem Recovering communities in Stochastic Block Model with more than sqrt(n) communities.
method Counting specific motifs to achieve polynomial-time community recovery above a new threshold.
result LDP fails below the new threshold, but polynomial-time recovery is possible above it.

Detection of dense cycles in graphs reveals a gap between easy detection and hard recovery.

problem Detecting and recovering dense cycles in Erdős-Rényi graphs.
method Characterization of computational thresholds for detection and recovery using low-degree polynomial algorithms.
result A gap exists between the detection and recovery thresholds for certain parameter regimes.

Paper studies vertex correspondence recovery in correlated graphs with node features.

problem Recovering hidden vertex correspondence between two correlated graphs with observed edge weights and node features.
method Introduced featured correlated Gaussian Wigner model and proposed QPAlign algorithm for quadratic programming relaxation.
result Characterized optimal information-theoretic thresholds for exact and partial recovery of latent mapping.