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Related papers: Refining local-type primordial non-Gaussianity: Sh…

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We investigate the effects of non-Gaussianity in the primordial density field on the reionization history. We rely on a semi-analytic method to describe the processes acting on the intergalactic medium (IGM), relating the distribution of…

Astrophysics · Physics 2010-03-26 D. Crociani , L. Moscardini , M. Viel , S. Matarrese

On very large scales, density fluctuations in the Universe are small, suggesting a perturbative model for large-scale clustering of galaxies (or other dark matter tracers), in which the galaxy density is written as a Taylor series in the…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-24 Patrick McDonald , Arabindo Roy

We use Bayesian inference and nested sampling to develop a non-parametric method to reconstruct the primordial power spectrum $P_{\mathcal{R}}(k)$ from Large Scale Structure (LSS) data. The performance of the method is studied by applying…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-16 G. Martínez-Somonte , A. Marcos-Caballero , E. Martínez-González , G. Cañas-Herrera

We study the non-Gaussianities generated by light axions, or compact scalar fields, during inflation. To correctly calculate their impact on primordial statistics, we will argue that it is necessary to account for the periodicity, or gauge…

High Energy Physics - Theory · Physics 2025-10-28 Priyesh Chakraborty

Non-Gaussianity in the primordial curvature perturbation is a crucial element of the early universe due to its significant impact on the primordial black hole (PBH) production. In this work, we focus on the effects of negative…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-08 Sayantan Choudhury , Kritartha Dey , Siddhant Ganguly , Ahaskar Karde , Swapnil Kumar Singh , Pranjal Tiwari

Working in an idealised framework in which a series of phases of evolution defined by the second slow-roll parameter $\eta$ are matched together, we calculate the reduced bispectrum, $f_{\rm NL}$, for models of inflation with a large peak…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-08 Matthew W. Davies , Pedro Carrilho , David J. Mulryne

We consider the expected level of primordial non-Gaussianities in models in which density perturbations are produced by spatial fluctuations in the decay rate of the inflaton. We consider both the non-Gaussianities resulting from the…

Astrophysics · Physics 2008-11-26 Matias Zaldarriaga

Observed kinematical data of 40 Local Group (LG) members are used to derive the dark matter halo mass of such galaxies. Haloes are selected from the theoretically expected LG mass function and two different density profiles are assumed, a…

Astrophysics of Galaxies · Physics 2015-06-17 Chris B. Brook , Arianna Di Cintio

Aims: We outline the Bayesian approach to inferring f_NL, the level of non-Gaussianity of local type. Phrasing f_NL inference in a Bayesian framework takes advantage of existing techniques to account for instrumental effects and foreground…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-23 Franz Elsner , Benjamin D. Wandelt , Michael D. Schneider

Understanding how galaxies trace the underlying matter density field is essential for characterizing the influence of the large-scale structure on galaxy formation, being therefore a key ingredient in observational cosmology. This…

We determine the abundance of primordial black holes (PBHs) formed in the context of non-gaussian models with primordial density perturbations. We consider models with a renormalized $\chi^2$ probability distribution function parametrized…

Astrophysics · Physics 2013-05-29 P. P. Avelino

The cosmic microwave background (CMB) temperature bispectrum is currently the most precise tool for constraining primordial non-Gaussianity (NG). The Planck temperature data tightly constrain the amplitude of local-type NG: $f_{\rm NL}^{\rm…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-06 J. Colin Hill

We study the non-Gaussianity and secondary Gravitational Waves (GWs) in the process of the Primordial Black Holes (PBHs) production from inflation. In our work, we focus on the $\alpha$-attractor inflation model in which a tiny bump in the…

General Relativity and Quantum Cosmology · Physics 2022-08-31 Kazem Rezazadeh , Zeinab Teimoori , Saeid Karimi , Kayoomars Karami

Here, generation of PBHs and secondary GWs from non-canonical inflation with quartic potential have been probed. It is illustrated that, quartic potential in non-canonical setup with a generalized power-law Lagrangian density can source a…

General Relativity and Quantum Cosmology · Physics 2024-02-08 Soma Heydari , Kayoomars Karami

A detection of primordial non-Gaussianity could transform our understanding of the fundamental theory of inflation. The precision promised by upcoming CMB and large-scale structure surveys raises a natural question: if a detection given a…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-04 Joyce Byun , Rachel Bean

Surveys of the matter distribution contain `fossil' information on possible non-Gaussianity that is generated in the primordial Universe. This primordial signal survives only on the largest scales where cosmic variance is strongest. By…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-10 Sheean Jolicoeur , Roy Maartens , Simthembile Dlamini

We study quintessential inflation using a generalized exponential potential $V(\phi)\propto exp(-\lambda \phi^n/Mpl^n), n>1$, the model admits slow-roll inflation at early times and leads to close-to-scaling behaviour in the post…

General Relativity and Quantum Cosmology · Physics 2017-06-21 Chao-Qiang Geng , Chung-Chi Lee , M. Sami , Emmanuel N. Saridakis , Alexei A. Starobinsky

The primordial non-Gaussianity of local type affects the clustering of dark matter halos, and the planned deep and wide photometric surveys are suitable for examining this class of non-Gaussianity. In our previous paper, we investigated the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Yoshitaka Takeuchi , Kiyotomo Ichiki , Takahiko Matsubara

We develop an analysis pipeline for characterizing the topology of large scale structure and extracting cosmological constraints based on persistent homology. Persistent homology is a technique from topological data analysis that quantifies…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-14 Matteo Biagetti , Alex Cole , Gary Shiu

Relativistic and free-streaming particles like neutrinos leave imprints in large scale structures (LSS), providing probes of the effective number of neutrino species $N_{\rm eff}$. In this paper, we use the Fisher formalism to forecast…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-02 Yanlong Shi , Chen Heinrich , Olivier Doré
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