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We study the ability of future weak lensing (WL) surveys to constrain primordial non-Gaussianity of the local type. We use a large ensemble of simulated WL maps with survey specifications relevant to Euclid and LSST. The simulations assume…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-05 Stefan Hilbert , Laura Marian , Robert E. Smith , Vincent Desjacques

We present a novel approach to estimate the value of primordial non-Gaussianity ($f_{\rm NL}$) parameter directly from the Cosmic Microwave Background (CMB) maps using a convolutional neural network (CNN). While traditional methods rely on…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-26 Chandan G. Nagarajappa , Yin-Zhe Ma

When constraining the primordial non-Gaussianity parameter f_NL with cosmic microwave background anisotropy maps, the bias resulting from the covariance between primordial non-Gaussianity and secondary non-Gaussianities to the estimator of…

Astrophysics · Physics 2008-11-26 Paolo Serra , Asantha Cooray

Tighter constraints on measurements of primordial non-Gaussianity will allow the differentiation of inflationary scenarios. The cosmic microwave background bispectrum-the standard method of measuring the local non-Gaussianity-is limited by…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-15 Zahra Gomes , Stefano Camera , Matt J. Jarvis , Catherine Hale , José Fonseca

Potential evidence for primordial non-Gaussianity (PNG) is expected to lie in the largest scales mapped by cosmological surveys. Forthcoming 21cm intensity mapping experiments will aim to probe these scales by surveying neutral hydrogen…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-20 Steven Cunnington , Stefano Camera , Alkistis Pourtsidou

We use data from the WMAP temperature maps to constrain a scale-dependent generalization of the popular 'local' model for primordial non-Gaussianity. In the model where the parameter fNL is allowed to run with scale k, fNL(k) = fNL*…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-16 Adam Becker , Dragan Huterer

We study the impact of the cosmological parameters uncertainties on the measurements of primordial non-Gaussianity through the large-scale non-Gaussian halo bias effect. While this is not expected to be an issue for the standard LCDM model,…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 Carmelita Carbone , Olga Mena , Licia Verde

The simplest models of inflation predict small non-gaussianities and a featureless power spectrum. However, there exist a large number of well-motivated theoretical scenarios in which large non-gaussianties could be generated. In general,…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-11 Stefano Gariazzo , Laura Lopez-Honorez , Olga Mena

We investigate optimization strategies to measure primordial non-Gaussianity with future spectroscopic surveys. We forecast measurements coming from the 3D galaxy power spectrum and compute constraints on primordial non-Gaussianity…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-26 Alvise Raccanelli , Olivier Dore , Neal Dalal

[Abridged]: A detection or nondetection of primordial non-Gaussianity by using the CMB data is crucial not only to discriminate inflationary models but also to test alternative scenarios. Non-Gaussianity offers, therefore, a powerful probe…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-14 A. Bernui , M. J. Reboucas

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

We revisit the predictions for the expected Cosmic Microwave Background bispectrum signal from the primary-lensing-Rees-Sciama correlation; we point out that it can be a significant contaminant to the bispectrum signal from primordial…

Cosmology and Nongalactic Astrophysics · Physics 2009-12-09 Anna Mangilli , Licia Verde

We propose a method to probe higher-order correlators of the primordial density field through the inhomogeneity of local non-Gaussian parameters, such as f_NL, measured within smaller patches of the sky. Correlators between n-point…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-28 Christian T. Byrnes , Sami Nurmi , Gianmassimo Tasinato , David Wands

The cosmic microwave background radiation is supposed to be Gaussian and this hypothesis is in good agreement with the recent very accurate measurements. Nonetheless a tiny amount of non-Gaussianity is predicted by the standard inflation…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-06 Davide Pietrobon

We analyze the 3-year WMAP data and look for a deviation from Gaussianity in the form of a 3-point function that has either of the two theoretically motivated shapes: local and equilateral. There is no evidence of departure from Gaussianity…

Astrophysics · Physics 2009-11-11 Paolo Creminelli , Leonardo Senatore , Matias Zaldarriaga , Max Tegmark

In this paper we present forecasts of the contamination on different shapes of the primordial non-Gaussianity fnl parameter -- detectable on future Cosmic Microwave Background (CMB) high--resolution anisotropy maps -- produced by unresolved…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 A. Curto , M. Tucci , J. Gonzalez-Nuevo , L. Toffolatti , E. Martinez-Gonzalez , F. Argueso , A. Lapi , M. Lopez-Caniego

We present a Gaussianity analysis of the WMAP 5-year Cosmic Microwave Background (CMB) temperature anisotropy data maps. We use several third order estimators based on the spherical Mexican hat wavelet. We impose constraints on the local…

We present an analysis of the constraints on the amplitude of primordial non-Gaussianity of local type described by the dimensionless parameter $f_{\rm NL}$. These constraints are set by the auto-correlation functions (ACFs) of two large…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-11 Jun-Qing Xia , Anna Bonaldi , Carlo Baccigalupi , Gianfranco De Zotti , Sabino Matarrese , Licia Verde , Matteo Viel

We outline the expected constraints on non-Gaussianity from the cosmic microwave background (CMB) with current and future experiments, focusing on both the third (f_{NL}) and fourth-order (g_{NL} and \tau_{NL}) amplitudes of the local…

Cosmology and Nongalactic Astrophysics · Physics 2010-07-27 Joseph Smidt , Alexandre Amblard , Christian T. Byrnes , Asantha Cooray , Alan Heavens , Dipak Munshi

A non-Gaussian detection in the WMAP 1-year data is reported. The detection has been found in the combined Q-V-W map proposed by the WMAP team (Komatsu et al. 2003) after applying a wavelet technique based on the Spherical Mexican Hat…

Astrophysics · Physics 2008-11-26 P. Vielva , E. Martinez-Gonzalez , R. B. Barreiro , J. L. Sanz , L. Cayon