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The perturbations in the electron number density during recombination contributes to the Cosmic Microwave Background bispectrum through second order terms. Perturbations in the electron density can be a factor of ~5 larger than the baryon…

Astrophysics · Physics 2010-04-21 Rishi Khatri , Benjamin D. Wandelt

This paper proposes a new sparse array source enumeration algorithm for underdetermined scenarios with more sources than sensors. The proposed algorithm decomposes the wideband signals into multiple uncorrelated frequency bands, computes…

Signal Processing · Electrical Eng. & Systems 2019-12-30 Yang Liu , John R. Buck

We address the dual challenge of estimating deviations from Gaussianity arising in models of the Early Universe, whilst retaining information necessary to assess whether a detection of non-Gaussianity is primordial. We do this by…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Dipak Munshi , Alan Heavens

Random graph mixture models are now very popular for modeling real data networks. In these setups, parameter estimation procedures usually rely on variational approximations, either combined with the expectation-maximisation (\textsc{em})…

Statistics Theory · Mathematics 2010-12-09 Christophe Ambroise , Catherine Matias

Seemingly unrelated linear regression models are introduced in which the distribution of the errors is a finite mixture of Gaussian components. Identifiability conditions are provided. The score vector and the Hessian matrix are derived.…

Methodology · Statistics 2014-03-18 Giuliano Galimberti , Elena Scardovi , Gabriele Soffritti

We present a detailed implementation of two bispectrum estimation methods which can be applied to general non-separable primordial and CMB bispectra. The method exploits bispectrum mode decompositions on the domain of allowed wavenumber or…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 J. R. Fergusson , M. Liguori , E. P. S. Shellard

We investigate whether a Gaussian likelihood, as routinely assumed in the analysis of cosmological data, is supported by simulated survey data. We define test statistics, based on a novel method that first destroys Gaussian correlations in…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-15 Elena Sellentin , Alan F. Heavens

The concept of biased data is well known and its practical applications range from social sciences and biology to economics and quality control. These observations arise when a sampling procedure chooses an observation with probability that…

Statistics Theory · Mathematics 2007-06-13 Sam Efromovich

RNA-Seq data characteristically exhibits large variances, which need to be appropriately accounted for in the model. We first explore the effects of this variability on the maximum likelihood estimator (MLE) of the overdispersion parameter…

Methodology · Statistics 2015-12-03 Luis Leon-Novelo , Claudio Fuentes , Sarah Emerson

Markov networks are frequently used in sciences to represent conditional independence relationships underlying observed variables arising from a complex system. It is often of interest to understand how an underlying network differs between…

Methodology · Statistics 2021-04-26 Byol Kim , Song Liu , Mladen Kolar

Long-baseline optical interferometry uses the power spectrum and bispectrum constructs as fundamental observables. Noise arising in the detection of the fringe pattern gives rise to both variance and biases in the power spectrum and…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 J. A. Gordon , D. F. Buscher

Owing to their more extensive sky coverage and tighter control on systematic errors, future deep weak lensing surveys should provide a better statistical picture of the dark matter clustering beyond the level of the power spectrum. In this…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Dipak Munshi , Joseph Smidt , Alan Heavens , Peter Coles , Asantha Cooray

This paper develops bootstrap methods to construct uniform confidence bands for nonparametric spectral estimation of L\'{e}vy densities under high-frequency observations. We assume that we observe $n$ discrete observations at frequency…

Statistics Theory · Mathematics 2017-05-30 Kengo Kato , Daisuke Kurisu

We revisit the source image estimation problem from blind source separation (BSS). We generalize the traditional minimum distortion principle to maximum likelihood estimation with a model for the residual spectrograms. Because residual…

Audio and Speech Processing · Electrical Eng. & Systems 2020-09-14 Robin Scheibler

In this study, a multiple-comparison approach is developed for detecting faint hyperspectral sources. The detection method relies on a sparse and non-negative representation on a highly coherent dictionary to track a spatially varying…

Methodology · Statistics 2017-05-24 Raphael Bacher , Celine Meillier , Florent Chatelain , Olivier Michel

The estimation of directed couplings between the nodes of a network from indirect measurements is a central methodological challenge in scientific fields such as neuroscience, systems biology and economics. Unfortunately, the problem is…

Machine Learning · Computer Science 2025-01-28 Louis Rouillard , Luca Ambrogioni , Demian Wassermann

Linear structural equation models postulate noisy linear relationships between variables of interest. Each model corresponds to a path diagram, which is a mixed graph with directed edges that encode the domains of the linear functions and…

Statistics Theory · Mathematics 2018-05-16 Mathias Drton , Christopher Fox , Andreas Käufl , Guillaume Pouliot

We consider how measurements of the 21cm radiation from the epoch of reionization (z=8-12) can constrain the amplitudes of various `shapes' of primordial non-Gaussianity. The limits on these shapes, each parametrized by the non-linear…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Sirichai Chongchitnan

Higher-order clustering statistics, like the galaxy bispectrum, can add complementary cosmological information to what is accessible with two-point statistics, like the power spectrum. While the standard way of measuring the bispectrum…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-14 Joyce Byun , Andrea Oddo , Cristiano Porciani , Emiliano Sefusatti

We investigate the constraints on primordial non-Gaussianity with varied bispectrum shapes that can be derived from the power spectrum of galaxies and clusters of galaxies detected in future wide field optical/near-infrared surveys. Having…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Cosimo Fedeli , Carmelita Carbone , Lauro Moscardini , Andrea Cimatti
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