English
Related papers

Related papers: Scale-Dependent Galaxy Bias from Massive Particles…

200 papers

We revisit alternative mechanisms of gravitational wave production during inflation and argue that they generically emit a non-negligible amount of scalar fluctuations. We find the scalar power is larger than the tensor power by a factor of…

High Energy Physics - Theory · Physics 2015-04-21 Mehrdad Mirbabayi , Leonardo Senatore , Eva Silverstein , Matias Zaldarriaga

We demonstrate that local, scale-dependent non-Gaussianity can generate cosmic variance uncertainty in the observed spectral index of primordial curvature perturbations. In a universe much larger than our current Hubble volume, locally…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Joseph Bramante , Jason Kumar , Elliot Nelson , Sarah Shandera

We analyse the efficiency of future large scale structure surveys to unveil the presence of scale dependent features in the primordial spectrum --resulting from cosmic inflation-- imprinted in the distribution of galaxies. Features may…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-04 Gonzalo A. Palma , Domenico Sapone , Spyros Sypsas

Primordial non-Gaussianities from multi-field inflation are a leading target for cosmological observations, because of the possible large correlations generated between long and short distances. These signatures are captured by the local…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-31 Dong-Gang Wang , Guilherme L. Pimentel , Ana Achúcarro

The primordial spectrum of fluctuations may present a large peak as a result of enhancing features during inflation. This may include, but is not limited to, bumps in the inflaton's potential, phases of ultra-slow-roll or turns in…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-30 Shyam Balaji , Guillem Domenech , Joseph Silk

The detection of Primordial Gravitational Waves (PGWs) is one of the most important goals of modern cosmology since PGWs can both provide substantial evidence for primordial inflation and shed light on its physical nature. Small scale…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-17 William Giarè , Alessandro Melchiorri

Primordial non-Gaussianity generated in an inflationary model where inflation is preceded by a radiation era is discussed. It is shown that both bispectrum and trispectrum non-Gaussianities are enhanced due to the presence of…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-04 Suratna Das

While large scale primordial non-Gaussianity is strongly constrained by present-day data, there are no such constraints at Mpc scales. Here we investigate the effect of significant small-scale primordial non-Gaussianity on structure…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-25 Clément Stahl , Thomas Montandon , Benoit Famaey , Oliver Hahn , Rodrigo Ibata

An inflationary model can be constrained by non-gaussian statistics as a parameter in the LSS (Large Scale Structure) distribution, and in the radiation of CMB (Cosmic Microwave Background) fluctuating temperature. Data on the CMB from…

General Relativity and Quantum Cosmology · Physics 2025-12-11 A. Agung , U. Sambiri , G. Hikmawan , F. P. Zen

The recently released data by pulsar timing array (PTA) collaborations present strong evidence for a stochastic signal consistent with a gravitational-wave background. Assuming this signal originates from scalar-induced gravitational waves,…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-27 Lang Liu , Zu-Cheng Chen , Qing-Guo Huang

We present a systematic study of galaxy bias in the presence of primordial non-Gaussianity in General Relativity (GR) at second order in perturbation theory. The non-linearity of the Poisson equation in GR and primordial non-Gaussianity are…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-08 Obinna Umeh , Kazuya Koyama

Inflationary cosmology is the leading explanation of the very early universe. Many different models of inflation have been constructed which fit current observational data. In this work theoretical and numerical methods for constraining the…

Cosmology and Nongalactic Astrophysics · Physics 2010-06-29 Ian Huston

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

The motion of a pseudo-scalar field $X$ during inflation naturally induces a significant amplification of the gauge fields to which it is coupled. The amplified gauge fields can source characteristic scalar and tensor primordial…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 Marco Peloso , Lorenzo Sorbo , Caner Unal

In this work we study the simultaneous effect of primordial non-Gaussianity and the modification of the gravity in $f(R)$ framework on large scale structure observations. We show that non-Gaussianity and modified gravity introduce a scale…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-12 Nareg Mirzatuny , Shahram Khosravi , Shant Baghram , Hossein Moshafi

Correlated adiabatic and isocurvature perturbation modes are produced during inflation through an oscillation mechanism when extra scalar degrees of freedom other than the inflaton field are present. We show that this correlation…

High Energy Physics - Phenomenology · Physics 2009-11-07 N. Bartolo , S. Matarrese , A. Riotto

Anisotropic stress perturbations induced by primordial Gaussian vector fields create non-Gaussianity in curvature perturbations. We found that such non-Gaussianity closely resembles the local-type non-Gaussianity parametrized by $f_{\rm…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-14 Maresuke Shiraishi , Shuichiro Yokoyama , Kiyotomo Ichiki , Takahiko Matsubara

[Abridged] We consider how galaxy clustering data, from Mpc to Gpc scales, from upcoming large scale structure surveys, such as Euclid and DESI, can provide discriminating information about the bispectrum shape arising from a variety of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Joyce Byun , Rachel Bean

We calculate the trispectrum of the primordial curvature perturbation generated by an epoch of slow-roll inflation in the early universe, and demonstrate that the non-gaussian signature imprinted at horizon crossing is unobservably small,…

Astrophysics · Physics 2010-10-27 David Seery , James E. Lidsey , Martin S. Sloth

Noncommutative geometry can provide effective description of physics at very short distances taking into account generic effects of quantum gravity. Inflation amplifies tiny quantum fluctuations in the early universe to macroscopic scales…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-18 Tomi S. Koivisto , David F. Mota