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Related papers: Non-Gaussianity Unleashed

200 papers

We apply the effective field theory approach to quasi-single field inflation, which contains an additional scalar field with Hubble scale mass other than inflaton. Based on the time-dependent spatial diffeomorphism, which is not broken by…

High Energy Physics - Theory · Physics 2015-06-12 Toshifumi Noumi , Masahide Yamaguchi , Daisuke Yokoyama

We consider a type of k-inflation under the Hamilton-Jacobi approach. We calculate various observables such as the scalar power spectrum, the tensor-to-scalar ratio, the scalar spectra index for the case where the Hubble parameter is a…

General Relativity and Quantum Cosmology · Physics 2024-06-27 Rong-Jia Yang , Ming Liu

In this paper, we study non-Gaussianity generated by a single scalar field in slow-roll inflation in the framework of the non-relativistic general covariant Ho\v{r}ava-Lifshitz theory of gravity with the projectability condition and an…

High Energy Physics - Theory · Physics 2013-05-30 Yongqing Huang , Anzhong Wang

We demonstrate that in the presence of a light scalar spectator field, vacuum transitions taking place during inflation can produce large, potentially detectable non-Gaussian signatures in the primordial curvature perturbation. Such…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-27 Björn Garbrecht , Pulkit S. Ghoderao , Arttu Rajantie

We explore the super-horizon evolution of the two-point and three-point correlation functions of the primordial density perturbation in randomly-generated multi-field potentials. We use the Transport method to evolve perturbations and give…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Jonathan Frazer , Andrew R Liddle

We give a concise formula for the non-Gaussianity of the primordial curvature perturbation generated on super-horizon scales in multi-scalar inflation model without assuming slow-roll conditions. This is an extension of our previous work.…

Astrophysics · Physics 2013-01-11 Shuichiro Yokoyama , Teruaki Suyama , Takahiro Tanaka

We study nonlinear cosmological perturbations and their possible non-Gaussian character in an extended non-minimal inflation where gravity is coupled non-minimally to both the scalar field and its derivatives. By expansion of the action up…

General Relativity and Quantum Cosmology · Physics 2019-10-09 Raheleh Shojaee , Kourosh Nozari , Farhad Darabi

In this work, we investigate the Hamilton-Jacobi formalism for non-minimally coupled inflation, focusing on the methodological frame-dependence arising from its application in the Jordan and Einstein frames. We systematically compare the…

General Relativity and Quantum Cosmology · Physics 2025-11-06 Feng-Yi Zhang , Li-Yang Chen , Rongrong Zhai

We construct a class of random potentials for N >> 1 scalar fields using non-equilibrium random matrix theory, and then characterize multifield inflation in this setting. By stipulating that the Hessian matrices in adjacent coordinate…

High Energy Physics - Theory · Physics 2014-12-02 M. C. David Marsh , Liam McAllister , Enrico Pajer , Timm Wrase

We generalize the effective field theory of single clock inflation to include dissipative effects. Working in unitary gauge we couple a set of composite operators in the effective action which is constrained solely by invariance under…

High Energy Physics - Theory · Physics 2015-05-30 Diana Lopez Nacir , Rafael A. Porto , Leonardo Senatore , Matias Zaldarriaga

In the present paper, certain inflation models are shown to have large non-Gaussianity in special cases. Namely, finite length inflation models with an effective higher derivative interaction, in which slow-roll inflation is adopted as…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-26 Shiro Hirai , Tomoyuki Takami

Using the "$\delta N$-formalism", We obtain the expression of the non-Gaussianity of multiple-field inflationary models with the nontrivial field-space metric. Further, we rewritten the result by using the slow-rolling approximation.

Astrophysics · Physics 2009-11-11 C. Y. Sun , D. H. Zhang

We conduct a thorough study of the comoving curvature perturbation $\mathcal{R}$ in single-field inflation with two stages, represented by a piecewise quadratic potential, where both the first and second derivatives are allowed to be…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-23 Xinpeng Wang , Xiao-Han Ma , Misao Sasaki

We calculate Large Scale Structure observables for non-Gaussianity arising from non-Bunch-Davies initial states in single field inflation. These scenarios can have substantial primordial non-Gaussianity from squeezed (but observable)…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Ivan Agullo , Sarah Shandera

We study an inflationary scenario with a two-form field to which an inflaton couples non-trivially. First, we show that anisotropic inflation can be realized as an attractor solution and that the two-form hair remains during inflation. A…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-16 Junko Ohashi , Jiro Soda , Shinji Tsujikawa

Cosmic inflation may have led to non-Gaussian initial conditions that cannot be fully parametrised by 3- and/or 4-point functions. In this work, we discuss various strategies to search for primordial non-Gaussianity beyond polyspectra with…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-03 Gonzalo A. Palma , Bruno Scheihing Hitschfeld , Spyros Sypsas

We consider a two component hybrid inflation model, in which two fields drive inflation. Our results show that this model generates an observable non-gaussian contribution to the curvature spectrum, within the limits allowed by the recent…

Astrophysics · Physics 2009-11-11 Laila Alabidi

Primordial non-Gaussianity encodes valuable information about the physics of inflation, including the spectrum of particles and interactions. Significant improvements in our understanding of non-Gaussanity beyond Planck require information…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-12 Jérôme Gleyzes , Roland de Putter , Daniel Green , Olivier Doré

We present a novel method for calculating the primordial non-Gaussianity produced by super-horizon evolution during inflation. Our method evolves the distribution of coarse-grained inflationary field values using a transport equation. We…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 David J. Mulryne , David Seery , Daniel Wesley

The effect of self-interactions of heavy scalar fields during inflation on the primordial non-Gaussianity is studied. We take a specific constant-turn quasi-single field inflation as an example. We derive an effective theory with emphasis…

High Energy Physics - Theory · Physics 2015-06-16 Jinn-Ouk Gong , Shi Pi , Misao Sasaki