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We propose a new method for extracting the non-Gaussian signatures on the isotemperature statistics in the cosmic microwave background (CMB) sky, which is induced by the gravitational lensing due to the intervening large-scale structure of…

Astrophysics · Physics 2009-11-06 Masahiro Takada

The new generation of galaxy surveys will provide unprecedented data allowing us to test gravity at cosmological scales. A robust cosmological analysis of the large-scale structure demands exploiting the nonlinear information encoded in the…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-13 Jorge Enrique García-Farieta , Héctor J Hortúa , Francisco-Shu Kitaura

Constraining primordial non-Gaussianities (PNGs) in the large-scale cosmic structure (LSS) is an important step in understanding properties of the early universe, specifically in distinguishing between different inflationary models.…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-14 Ethan Vislosky , Zachery Brown , Regina Demina , Edmond Chaussidon

One of the fundamental problems in extracting the cosmic microwave background signal (CMB) from millimeter/submillimeter observations is the pollution by emission from the Milky Way: synchrotron, free-free, and thermal dust emission. To…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 H. U. Nørgaard - Nielsen

With the release of the data from the Boomerang and MAXIMA-1 balloon flights, estimates of cosmological parameters based on the Cosmic Microwave Background (CMB) have reached unprecedented precision. In this paper I show that it is possible…

Astrophysics · Physics 2009-10-31 William H. Kinney

We present a further development of a method for accelerating the calculation of CMB power spectra, matter power spectra and likelihood functions for use in cosmological Bayesian inference. The algorithm, called {\sc CosmoNet}, is based on…

Astrophysics · Physics 2009-11-13 T. Auld , M. Bridges , M. P. Hobson

Big bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) anisotropies independently predict the universal baryon density. Comparing their predictions will provide a fundamental test on cosmology. Using BBN and the CMB…

Astrophysics · Physics 2009-11-07 Richard H. Cyburt

We propose an efficient Bayesian MCMC algorithm for estimating cosmological parameters from CMB data without use of likelihood approximations. It builds on a previously developed Gibbs sampling framework that allows for exploration of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-29 Benjamin Racine , Jeffrey B. Jewell , Hans Kristian K. Eriksen , Ingunn K. Wehus

We propose a lightweight deep convolutional neural network (lCNN) to estimate cosmological parameters from simulated three-dimensional dark matter (DM) halo distributions and associated statistics. The training dataset comprises 2000…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-20 Zhiwei Min , Xu Xiao , Jiacheng Ding , Liang Xiao , Jie Jiang , Donglin Wu , Qiufan Lin , Yang Wang , Shuai Liu , Zhixin Chen , Xiangru Li , Jinqu Zhang , Le Zhang , Xiao-Dong Li

We describe a novel method for the application of Convolutional Neural Networks (CNNs) to fields defined on the sphere, using the HEALPix tessellation scheme. Specifically, We have developed a pixel-based approach to implement convolutional…

Instrumentation and Methods for Astrophysics · Physics 2019-08-21 Nicoletta Krachmalnicoff , Maurizio Tomasi

The statistical properties of a map of the primary fluctuations in the cosmic microwave background (CMB) may be specified to high accuracy by a few thousand power spectra measurements, provided the fluctuations are gaussian, yet the number…

Astrophysics · Physics 2009-11-07 Sujata Gupta , Alan F. Heavens

Two different predictions for the primordial curvature fluctuation bispectrum are compared through their effects on the Cosmic Microwave Background temperature fluctuations. The first has a local form described by a single parameter f_{NL}.…

Astrophysics · Physics 2009-06-23 Ian G Moss , Chris M Graham

We explore the possibility of detecting primordial non-Gaussianity of the local type using weak lensing peak counts. We measure the peak abundance in sets of simulated weak lensing maps corresponding to three models f_NL={0, +100, -100}.…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-19 Laura Marian , Stefan Hilbert , Robert E. Smith , Peter Schneider , Vincent Desjacques

The statistics of large-scale structure in the Universe can be used to probe non-Gaussianity of the primordial density field, complementary to existing constraints from the cosmic microwave background. In particular, the scale dependence of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Gianmassimo Tasinato , Matteo Tellarini , Ashley J. Ross , David Wands

The discovery of cosmic microwave background (CMB) was a paradigm shift in the study and fundamental understanding of the early universe and also the Big Bang phenomenon. Cosmic microwave background is one of the richest and intriguing…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-11 Amit Mishra , Pranath Reddy , Rahul Nigam

We present limits to the amplitude of non-Gaussian primordial fluctuations in the WMAP 1-year cosmic microwave background sky maps. A non-linear coupling parameter, f_NL, characterizes the amplitude of a quadratic term in the primordial…

We consider primordial non-Gaussianity due to quadratic corrections in the gravitational potential parametrized by a non-linear coupling parameter fnl. We study constraints on fnl from measurements of the galaxy bispectrum in redshift…

Astrophysics · Physics 2009-11-10 Roman Scoccimarro , Emiliano Sefusatti , Matias Zaldarriaga

We describe a Bayesian framework for estimating the time-domain noise covariance of CMB observations, typically parametrized in terms of a 1/f frequency profile. This framework is based on the Gibbs sampling algorithm, which allows for…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 I. K. Wehus , S. K. Næss , H. K. Eriksen

We present a method to reconstruct the initial linear-regime matter density field from the late-time non-linearly evolved density field in which we channel the output of standard first-order reconstruction to a convolutional neural network…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-23 Christopher J. Shallue , Daniel J. Eisenstein

A detection or nondetection of primordial non-Gaussianity in the CMB data is essential not only to test alternative models of the physics of the early universe but also to discriminate among classes of inflationary models. Given this far…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-15 A. Bernui , M. J. Reboucas