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If cosmic inflation suffered tiny time-dependent deviations from the slow-roll regime, these would induce the existence of small scale-dependent features imprinted in the primordial spectra, with their shapes and sizes revealing information…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 Sander Mooij , Gonzalo A. Palma , Grigoris Panotopoulos , Alex Soto

We analyze multi-field inflationary systems which yield strongly scale dependent non-Gaussianity with a shape that is very close to the local shape. As in usual multi-field models, the non-Gaussianity arises from the non-linear transfer of…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-27 Jason Kumar , Louis Leblond , Arvind Rajaraman

Primordial non-Gaussianity is one of the most powerful probes of the inflationary epoch. The particle spectrum relevant to inflation, including masses and spins, is encoded in the precise form of statistical correlations of the adiabatic…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-03 Eugene Chen , Daniel Green , Vincent S. H. Lee

Astrophysical observations indicate that the ``Local Universe" has a relatively lower matter density ($\Omega_0$) than the predictions of the standard inflation cosmology and the large-scale motions of galaxies which provide a mean mass…

Astrophysics · Physics 2016-08-30 Xiang-Ping Wu , Zugan Deng , Zhenlong Zou , Li-Zhi Fang , Bo Qin

In the last few decades, advances in observational cosmology have given us a standard model of cosmology. We know the content of the universe to within a few percent. With more ambitious experiments on the way, we hope to move beyond the…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-26 Amit P. S. Yadav , Benjamin D. Wandelt

Several recent studies have shown how to properly calculate the observed clustering of galaxies in a relativistic context, and uncovered corrections to the Newtonian calculation that become significant on scales near the horizon. Here, we…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Donghui Jeong , Fabian Schmidt , Christopher M. Hirata

Strong gravitational lensing offers constraints on the Hubble constant that are independent of other methods. However, those constraints are subject to uncertainties in lens models. Previous studies suggest that using an elliptical power…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-02 Dilys Ruan , Charles R. Keeton

We study the tilt of the primordial gravitational waves spectrum. A hint of blue tilt is shown from analyzing the BICEP2 and POLARBEAR data. Motivated by this, we explore the possibilities of blue tensor spectra from the very early universe…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Yi Wang , Wei Xue

Primordial non-Gaussianity (PNG) is a signature of fundamental physics in the early universe that is probed by cosmological observations. It is well known that the local type of PNG generates a strong signal in the two-point function of…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-28 James M. Sullivan , Uros Seljak

Thanks to the rapid progress in precision cosmology in the last few years, we now have access to physical observables that may constrain the theory of inflation through the non-Gaussianity (NG) signatures in the cosmic microwave background…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-19 Xinghai Zhao , Yuexing Li , Sarah Shandera , Donghui Jeong

We derive a general expression for the probability of observing deviations from statistical isotropy in the cosmic microwave background (CMB) if the primordial fluctuations are non-Gaussian and extend to superhorizon scales. The primary…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-27 Saroj Adhikari , Sarah Shandera , Adrienne L. Erickcek

Analytic expressions for the statistics of peaks of random fields with weak non-Gaussianity are provided. Specifically, the abundance and spatial correlation of peaks are represented by formulas which can be evaluated only by virtually…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-04 Takahiko Matsubara

We show that modifications of Einstein gravity during inflation could leave potentially measurable imprints on cosmological observables in the form of non-Gaussian perturbations. This is due to the fact that these modifications appear in…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-22 Nicola Bartolo , Dario Cannone , Raul Jimenez , Sabino Matarrese , Licia Verde

This is a pedagogical review on primordial non-Gaussianities from inflation models. We introduce formalisms and techniques that are used to compute such quantities. We review different mechanisms which can generate observable large…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-10 Xingang Chen

It has recently been proposed that the large-scale bias of dark matter halos depends sensitively on primordial non-Gaussianity of the local form. In this paper we point out that the strong scale dependence of the non-Gaussian halo bias…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Carlos Cunha , Dragan Huterer , Olivier Dore

Primordial non-Gaussianity, in particular the coupling of modes with widely different wavelengths, can have a strong impact on the large-scale clustering of tracers through a scale-dependent bias with respect to matter. We demonstrate that…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-26 Fabian Schmidt

When inflation is driven by a pseudo-scalar field \chi coupled to vectors as \alpha/4 \chi F \tilde F, this coupling may lead to a copious production of gauge quanta, which in turns induces non-Gaussian and non-scale invariant corrections…

High Energy Physics - Theory · Physics 2013-05-22 Andrei Linde , Sander Mooij , Enrico Pajer

In this work we study the properties of the mass density field in the non-Gaussian world models simulated by Grossi et al. 2007. In particular we focus on the one-point density probability distribution function of the mass density field in…

Astrophysics · Physics 2010-03-26 M. Grossi , E. Branchini , K. Dolag , S. Matarrese , L. Moscardini

We consider the non-Gaussianity of the nonlinear density perturbations in a single-field inflationary model when a scalar field couples nonminimally with gravity. Gravity theories with a nonminimal coupling can be transformed into the…

Astrophysics · Physics 2007-05-23 Seoktae Koh

We study statistical anisotropies generated in the observed two-point function of the cosmic microwave background (CMB) fluctuations if the primordial statistics are non-Gaussian. Focusing on the dipole modulations of the anisotropies, we…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-17 Saroj Adhikari , Anne-Sylvie Deutsch , Sarah Shandera