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Related papers: The shape of primordial non-Gaussianity and the CM…

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We use Minkowski Functionals to explore the presence of non-Gaussian signatures in simulated cosmic microwave background (CMB) maps. Precisely, we analyse the non-Gaussianities produced from the angular power spectra emerging from a class…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-08 Camila P. Novaes , Micol Benetti , Armando Bernui

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 calculate the shape correlations between trispectra in various equilateral non-Gaussian models, including DBI inflation, ghost inflation and Lifshitz scalars, using the full trispectrum as well as the reduced trispectum. We find that…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-06 Keisuke Izumi , Shuntaro Mizuno , Kazuya Koyama

We consider contributions to non-Gaussianity of the Cosmic Microwave Background (CMB) from remnants of post-inflationary phase transitions in the very early universe. Such signatures can optimistically be used to discover evidence of new…

Astrophysics · Physics 2010-01-11 Alessandra Silvestri , Mark Trodden

The extensive search for deviations from Gaussianity in cosmic microwave background radiation (CMB) data is very important due to the information about the very early moments of the universe encoded there. Recent analyses from Planck CMB…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 C. P. Novaes , A. Bernui , I. S. Ferreira , C. A. Wuensche

The primordial non-Gaussian parameter fNL has been shown to be scale-dependent in several models of inflation with a variable speed of sound. Starting from a simple ansatz for a scale-dependent amplitude of the primordial curvature…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-06 Emiliano Sefusatti , Michele Liguori , Amit P. S. Yadav , Mark G. Jackson , Enrico Pajer

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

Cross-correlations between Cosmic Microwave Background (CMB) temperature and $y$-spectral distortions anisotropies have been previously proposed as a way to measure the local bispectrum parameter $f_{\rm NL}^{\rm loc.}$ in a range of scales…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-04 Andrea Ravenni , Michele Liguori , Nicola Bartolo , Maresuke Shiraishi

Gravitational waves from inflation induce polarization patterns in the cosmic microwave background (CMB). It is known that there are only two types of non-Gaussianities of the gravitaional waves in the most general scalar field theories…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-01 Hiroaki W. H. Tahara , Jun'ichi Yokoyama

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

We apply the time-renormalization group approach to study the effect of primordial non-Gaussianities in the non-linear evolution of cosmological dark matter density perturbations. This method improves the standard perturbation approach by…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Nicola Bartolo , J. P. Beltran Almeida , Sabino Matarrese , Massimo Pietroni , Antonio Riotto

We study the covariance in the angular power spectrum estimates of CMB fluctuations when the primordial fluctuations are non-Gaussian. The non-Gaussian covariance comes from a nonzero connected four-point correlation function -- or the…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-07 Saroj Adhikari , Dragan Huterer

The next generation of ground-based CMB experiments aim to measure temperature and polarization fluctuations up to $\ell_{\rm max} \approx 5000$ over half of the sky. Combined with Planck data on large scales, this will provide improved…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-01 William R. Coulton , P. Daniel Meerburg , David G. Baker , Selim Hotinli , Adriaan J. Duivenvoorden , Alexander van Engelen

Distortions in the primordial cosmic microwave background (CMB) along the line-of-sight can be modeled and described using 11 fields. These distortion fields correspond to various cosmological signals such as weak gravitational lensing of…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-06 Amit P. S. Yadav , Meng Su , Matias Zaldarriaga

We investigate the CMB $\mu$ distortion in models where two uncorrelated sources contribute to primordial perturbations. We parameterise each source by an amplitude, tilt, running and running of the running. We perform a detailed analysis…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-15 Kimmo Kainulainen , Juuso Leskinen , Sami Nurmi , Tomo Takahashi

Multi-field inflation models and non-Bunch-Davies vacuum initial conditions both predict sizeable non-Gaussian primordial perturbations and anisotropic $\mu$-type spectral distortions of the cosmic microwave background (CMB) blackbody.…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-23 Mathieu Remazeilles , Andrea Ravenni , Jens Chluba

A convincing detection of primordial non-Gaussianity in the local form of the bispectrum, whose amplitude is given by the fNL parameter, offers a powerful test of inflation. In this paper we calculate the modification of two-point…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Donghui Jeong , Eiichiro Komatsu , Bhuvnesh Jain

The rapidly improving precision of measurements of gravitational lensing of the Cosmic Microwave Background (CMB) also requires a corresponding increase in the precision of theoretical modeling. A commonly made approximation is to model the…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-24 Vanessa Böhm , Marcel Schmittfull , Blake D. Sherwin

We introduce a non-perturbative method to constrain the amplitude of local-type primordial non-Gaussianity ($f_{\rm NL}$) using squeezed configurations of the CMB lensing convergence and cosmic shear bispectra. First, we use cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-20 Samuel Goldstein , Oliver H. E. Philcox , J. Colin Hill , Angelo Esposito , Lam Hui

We study the effects of instrumental systematics on the estimation of primordial non-Gaussianity using the cosmic microwave background (CMB) bispectrum from both the temperature and the polarization anisotropies. For temperature systematics…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-07 Meng Su , Amit P. S. Yadav , Meir Shimon , Brian G. Keating