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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.

168,657 papers · 148 categories

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83167250333 · Jun 202019922001200920172026
48 results for Sparse probabilities

Evidential Softmax preserves multimodality in sparse probability distributions for generative models.

problem Sparse probability distributions in deep generative models make exact marginalization computationally intractable.
method Introduce ev-softmax, a sparse normalization function that preserves multimodality and can be trained with probabilistic loss functions.
result ev-softmax outperforms existing techniques in distributional accuracy and dimensionality reduction.

Paper connects probability density cuts to graph theory eigenfunctions.

problem Developing sparse cuts for probability densities.
method Defines sparse cuts and principal eigenfunctions for probability densities, proving Cheeger and Buser inequalities.
result No such inequalities hold for prior definitions, proving new inequalities for probability densities.

Proposes novel wSVMs for sparse learning and accurate probability estimation.

problem Sparse features with redundant noise limit the performance of existing wSVMs.
method Develops 1\ell^1-norm and elastic net regularized wSVMs for automatic variable selection and probability estimation.
result Elastic net regularized wSVMs achieve superior performance in variable selection and probability estimation.

A two-phase algorithm identifies the best arm in sparse linear bandits with fixed budget.

problem Best arm identification in sparse linear bandits with limited budget.
method Lasso and Optimal-Design (Lasso-OD) based linear best-arm identification.
result Lasso-OD achieves significant performance improvement for sparse and high-dimensional linear bandits.

Although many successful ensemble clustering approaches have been developed in recent years, there are still two limitations to most of the existing approaches. First, they mostly overlook the issue of uncertain links, which may mislead the overall consensus process. Second, they generally lack the ability to incorpora…

2016-06-03abs ↗pdf ↗

Random non-linear Fourier features have recently shown remarkable performance in a wide-range of regression and classification applications. Motivated by this success, this article focuses on a sparse non-linear Fourier feature (NFF) model. We provide a characterization of the sufficient number of data points that guar…

2020-02-12abs ↗pdf ↗

The paper studies PCA of probability measures with varying sample sizes and finds optimal convergence rates.

problem PCA of multiple probability measures with varying sample sizes.
method Double asymptotic regime analysis with convergence rates n1/2+mαn^{-1/2} + m^{-α} for empirical covariance and PCA risk.
result Optimal convergence rates for empirical covariance and PCA risk in the dense regime are proven.

We study the sparse entropy-regularized reinforcement learning (ERL) problem in which the entropy term is a special form of the Tsallis entropy. The optimal policy of this formulation is sparse, i.e.,~at each state, it has non-zero probability for only a small number of actions. This addresses the main drawback of the …

2018-02-10abs ↗pdf ↗

Paper presents a randomized algorithm for SPCA with high probability approximation.

problem Sparse Principal Component Analysis (SPCA) is NP-hard.
method Based on basic SDP relaxation, the algorithm constructs deterministic and randomized solutions.
result The algorithm achieves an approximation ratio of at most the sparsity constant with high probability.

This paper deals with the design of a sensing matrix along with a sparse recovery algorithm by utilizing the probability-based prior information for compressed sensing system. With the knowledge of the probability for each atom of the dictionary being used, a diagonal weighted matrix is obtained and then the sensing ma…

2019-10-27abs ↗pdf ↗

Many conventional statistical procedures are extremely sensitive to seemingly minor deviations from modeling assumptions. This problem is exacerbated in modern high-dimensional settings, where the problem dimension can grow with and possibly exceed the sample size. We consider the problem of robust estimation of sparse…

2017-02-24abs ↗pdf ↗

The paper extends and applies a new shrinkage prior in Bayesian factor analysis.

problem Estimating the number of factors in sparse Bayesian factor analysis.
method Introduces and extends a generalized cumulative shrinkage process (CUSP) prior.
result Exchangeable spike-and-slab shrinkage priors imply increasing shrinkage as the column index increases.

New method for community detection in sparse directed SBMs with exact recovery guarantees.

problem Exact recovery in sparse directed SBMs, especially with growing communities.
method Two-stage procedure: neighborhood-smoothing followed by KK-means clustering.
result Exact recovery of all community labels with probability tending to one under mild sparsity and separation conditions.

The paper provides entrywise bounds for Sparse PCA, improving upon previous results.

problem Sparse Principal Component Analysis (PCA) recovery error characterization in spectral or Frobenius norms.
method Entrywise 2,\ell_{2,\infty} bounds for Sparse PCA under general high-dimensional subgaussian design, using sparsistent algorithms.
result Improved entrywise bounds for Sparse PCA, finer characterization of estimation error.

New lower bounds show sparse recovery is hard even with multiple preconditioners.

problem Sparse recovery with ill-conditioned designs is hard for certain algorithms.
method Constructing a single signal distribution that multiple preconditioned Lasso programs fail on.
result Standard sparse random designs are robust to erasures, aiding sparse recovery.

In this note we discuss a common misconception, namely that embeddings are always used to reduce the dimensionality of the item space. We show that when we measure dimensionality in terms of information entropy then the embedding of sparse probability distributions, that can be used to represent sparse features or data…

2019-01-07abs ↗pdf ↗

In the present paper we study a sparse stochastic network enabled with a block structure. The popular Stochastic Block Model (SBM) and the Degree Corrected Block Model (DCBM) address sparsity by placing an upper bound on the maximum probability of connections between any pair of nodes. As a result, sparsity describes o…

2019-10-03abs ↗pdf ↗

In multi-instance (MI) learning, each object (bag) consists of multiple feature vectors (instances), and is most commonly regarded as a set of points in a multidimensional space. A different viewpoint is that the instances are realisations of random vectors with corresponding probability distribution, and that a bag is…

2018-03-07abs ↗pdf ↗

The study optimizes distribution estimation from samples with relative entropy error, adapting to sparse distributions.

problem Estimating discrete distributions with high-probability accuracy in relative entropy.
method Analysis of Laplace estimator and confidence-dependent smoothing techniques, including data-dependent smoothing.
result Optimal high-probability risk bounds for various estimators, including a new data-dependent smoothing method.

We introduce a balloon estimator in a generalized expectation-maximization method for estimating all parameters of a Gaussian mixture model given one data sample per mixture component. Instead of limiting explicitly the model size, this regularization strategy yields low-complexity sparse models where the number of eff…

2018-12-11abs ↗pdf ↗

Sparse representations have proven their efficiency in solving a wide class of inverse problems encountered in signal and image processing. Conversely, enforcing the information to be spread uniformly over representation coefficients exhibits relevant properties in various applications such as digital communications. A…

2015-12-18abs ↗pdf ↗

Study financial contagion and risk in sparse networks with directed edges.

problem Analyzing systemic risk in sparse financial networks with balance-sheet interactions.
method Linear fraction of institutions with zero out-degree, sender-truncated subgraph G_sh, adversarial and random systemic events, explicit fan-in accumulation bound.
result Maximal forward reachability in G_sh is O(log n) with high probability in the subcritical regime, and multi-hit defaults are negligible in the supercritical regime.

We review and illustrate how the volatility smile translates into a probability distribution, the market-implied probability distribution representing believes priced in. The effects of changes in the smile are examined. Special attention is given to the effects of slope, which might appear at first counter-intuitive. …

2009-11-04abs ↗pdf ↗

New model allows sparse graphs with many triangles to be represented.

problem Sparse graphs with many triangles cannot be accurately represented in finite dimensions.
method Infinite-dimensional inner product model with manifold representations.
result Local neighborhoods can be represented in lower dimensions.

We analyze the sample complexity of learning graphical games from purely behavioral data. We assume that we can only observe the players' joint actions and not their payoffs. We analyze the sufficient and necessary number of samples for the correct recovery of the set of pure-strategy Nash equilibria (PSNE) of the true…

2016-01-27abs ↗pdf ↗

Proposes a method to learn sparse deep neural networks with theoretical guarantees.

problem Over-parameterized deep neural networks cause training, prediction, and interpretation difficulties.
method Frequentist-like method for sparse DNNs under Bayesian framework.
result Consistent sparse DNNs with at most O(n/log(n))O(n/\log(n)) connections.

Paper introduces kernel deformed exponential families for sparse continuous attention.

problem Creating efficient attention mechanisms for sparse data.
method Developed kernel deformed exponential families, theoretically and experimentally.
result Kernel deformed exponential families can attend to multiple compact regions of data.

Neural network learning is usually time-consuming since backpropagation needs to compute full gradients and backpropagate them across multiple layers. Despite its success of existing works in accelerating propagation through sparseness, the relevant theoretical characteristics remain under-researched and empirical stud…

2019-05-24abs ↗pdf ↗

Develops a measure-theoretic framework for complex co-occurrence data.

problem Modeling and interpreting complex co-occurrences in high-dimensional data.
method Introduces measure-theoretic probability and conditional probability, investigates E-integrals.
result Establishes a rigorous measure-theoretic foundation for co-occurrence modeling.