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We have calculated the third order moments of scalar curvature perturbations in configuration space for different inflationary models. We developed a robust numerical technique to compute the bispectrum for different models that have some…

High Energy Physics - Theory · Physics 2015-08-26 M. Junaid , D. Pogosyan

We study the generation of local non-Gaussianity in models of canonical single field inflation when their backgrounds are either attractor or non-attractor. We show that the invariance of inflation under space-time diffeomorphisms can be…

High Energy Physics - Theory · Physics 2023-04-13 Rafael Bravo , Gonzalo A. Palma

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

It was pointed out recently that in some inflationary models quantum loops containing a scalar of mass $m$ that couples to the inflaton can be the dominant source of primordial non-Gaussianities. We explore this phenomenon in the simplest…

High Energy Physics - Phenomenology · Physics 2019-03-27 Haipeng An , Mark B. Wise , Zipei Zhang

We analytically derive a more accurate formula for the power spectrum of the biased objects with the primordial non-Gaussianity parameterized not only by the non-linearity parameter fNL, but also by gNL and tauNL which characterize the…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Shuichiro Yokoyama , Takahiko Matsubara

In single-field inflationary models the bispectra are usually given in the $\zeta$-gauge, because its temporal part leads to the super-horizon conservation of fluctuations. However, this property is independent of the choice of {\it…

High Energy Physics - Theory · Physics 2022-03-23 Ermis Mitsou , Jaiyul Yoo

We calculate the bispectrum of single-field braneworld inflation, triggered by either an ordinary scalar field or a cosmological tachyon, by means of a gradient expansion of large-scale non-linear perturbations coupled to stochastic…

Astrophysics · Physics 2007-05-23 Gianluca Calcagni

We compute the three-point correlation function of primordial scalar density perturbations in a general single-field inflationary scenario, where a scalar field phi has a direct coupling with the Ricci scalar R and the Gauss-Bonnet term GB.…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-22 Antonio De Felice , Shinji Tsujikawa

We perform a general study of primordial scalar non-Gaussianities in single field inflationary models in Einstein gravity. We consider models where the inflaton Lagrangian is an arbitrary function of the scalar field and its first…

High Energy Physics - Theory · Physics 2009-11-11 Xingang Chen , Min-xin Huang , Shamit Kachru , Gary Shiu

Assuming a LCDM universe in a single-field inflationary scenario, we compute the three-point correlation function of the observed matter density fluctuation in the squeezed triangular configuration, accounting for all the relativistic…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-25 Jaiyul Yoo , Nastassia Grimm , Ermis Mitsou

We compute the matter bispectrum in the presence of primordial local non-Gaussianity over a wide range of scales, including the very small nonlinear ones. We use the Halo Model approach, considering non-Gaussian corrections to the halo…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 D. G. Figueroa , E. Sefusatti , A. Riotto , F. Vernizzi

We construct an inflationary model that is consistent with both large non-Gaussianity and a running spectral index. The scenario of modulated inflation suggests that modulated perturbation can induce the curvature perturbation with a large…

High Energy Physics - Theory · Physics 2009-11-19 Tomohiro Matsuda

Next-generation galaxy and 21cm intensity mapping surveys will rely on a combination of the power spectrum and bispectrum for high-precision measurements of primordial non-Gaussianity. In turn, these measurements will allow us to…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-08 Roy Maartens , Sheean Jolicoeur , Obinna Umeh , Eline M. De Weerd , Chris Clarkson

We study the slow-roll inflation models, where the inflaton slow-rolls along a trajectory whose orthogonal directions are lifted by potentials with masses of order the Hubble parameter. In these models large non-Gaussianities can be…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-06 Xingang Chen , Yi Wang

We investigate the non-Gaussianity of primordial cosmological perturbations within our recently proposed holographic description of inflationary universes. We derive a holographic formula that determines the bispectrum of cosmological…

High Energy Physics - Theory · Physics 2011-05-16 Paul McFadden , Kostas Skenderis

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

We study the dependence on configuration in momentum space of the primordial 3-point function of density perturbations in several different scenarios: standard slow-roll inflation, curvaton and variable decay models, ghost inflation, models…

Astrophysics · Physics 2009-07-09 Daniel Babich , Paolo Creminelli , Matias Zaldarriaga

We analyze the signatures of inflationary models that are coupled to strongly interacting field theories, a basic class of multifield models also motivated by their role in providing dynamically small scales. Near the squeezed limit of the…

High Energy Physics - Theory · Physics 2015-06-12 Daniel Green , Matthew Lewandowski , Leonardo Senatore , Eva Silverstein , Matias Zaldarriaga

We calculate the three-point correlation function of the comoving curvature perturbation generated during an inflationary epoch driven by false vacuum energy. We get a novel false vacuum shape bispectrum, which peaks in the equilateral…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Jinn-Ouk Gong , Chunshan Lin , Yi Wang

We provide a formula for the scaling behaviour of the inflationary bispectrum in the 'squeezed' limit where one momentum becomes much smaller than the other two. This determines the scaling of the halo bias at low wavenumber and will be an…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Mafalda Dias , Raquel H. Ribeiro , David Seery
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