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Related papers: Holographic non-Gaussianities in general single-fi…

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A pressing problem in comparing inflationary models with observation is the accurate calculation of correlation functions. One approach is to evolve them using ordinary differential equations ("transport equations"), analogous to the…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-10 David Seery , David J. Mulryne , Jonathan Frazer , Raquel H. Ribeiro

We consider the description of the clustering of halos for physically-motivated types of non-Gaussian initial conditions. In particular we include non-Gaussianity of the type arising from single field slow-roll, multi fields, curvaton…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Licia Verde , Sabino Matarrese

We have studied modulated inflation that generates curvature perturbation from light-field fluctuation. As discussed in previous works, even if the fluctuation of the inflaton itself does not generate the curvature perturbation at the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Tomohiro Matsuda

In non-attractor single-field inflation models producing a scale-invariant power spectrum, the curvature perturbation on super-horizon scales grows as ${\cal R}\propto a^3$. This is so far the only known class of self-consistent…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Xingang Chen , Hassan Firouzjahi , Eiichiro Komatsu , Mohammad Hossein Namjoo , Misao Sasaki

We perform a thorough computation of the one-loop corrections from both scalar and tensor degrees of freedom to the power spectrum of curvature fluctuations for non-canonical Lagrangians in single-field inflation. We consider models…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-27 Nicola Bartolo , Emanuela Dimastrogiovanni , Alberto Vallinotto

We study implications of perturbative unitarity for quasi-single field inflation with the inflaton and one massive scalar. Analyzing high energy scattering, we show that non-Gaussianities with $|f_{\rm NL}|\gtrsim1$ cannot be realized…

High Energy Physics - Theory · Physics 2021-07-21 Suro Kim , Toshifumi Noumi , Keito Takeuchi , Siyi Zhou

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

We compute the non-Gaussianities that arise in single field, slow roll inflationary models arising from arbitrary homogeneous initial states, as well as subleading contributions to the power spectrum. Non Bunch-Davies vacuum initial states…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-12 Sina Bahrami , Éanna É. Flanagan

We study the evolution of cosmological perturbations on large scales, up to second order, for a perfect fluid with generic equation of state. Taking advantage of super-horizon conservation laws, it is possible to follow the evolution of the…

Astrophysics · Physics 2009-11-10 N. Bartolo , S. Matarrese , A. Riotto

We investigate the primordial non-Gaussianities from the trispectra in multi-field inflation models, which can be seen as generalization of multi-field $k$-inflation and multi-DBI inflation. We derive the full fourth-order perturbation…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-06 Xian Gao , Miao Li , Chunshan Lin

We present a new efficient method for computing the non-linearity parameters of the higher order correlation functions of local type curvature perturbations in inflation models having a $\cal N$-component scalar field, focusing on the…

Astrophysics · Physics 2014-11-18 Shuichiro Yokoyama , Teruaki Suyama , Takahiro Tanaka

If the expansion of the early Universe was not close to de Sitter, the statistical imprints of the primordial density perturbation on the cosmic microwave background can be quite different from those derived in slow-roll inflation. In this…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-05 Raquel H. Ribeiro

In the present paper, we study the non-Gaussianity of multiple-field inflation model using the method of the field equation. We start from reviewing the background and the perturbation theory of multiple-field inflation, and then derive the…

Astrophysics · Physics 2008-04-04 Shi-Wen Li , Wei Xue

The holographic entropy bound is used to estimate the quantum-gravitational discreteness of inflationary perturbations. In the context of scalar inflaton perturbations produced during standard slow-roll inflation, but assuming that…

Astrophysics · Physics 2009-11-07 Craig J. Hogan

The effective field theory (EFT) of inflation provides a natural framework to study the new physical effects on primordial perturbations. Recently a healthy extension of the EFT of inflation with high-order operators has been proposed,…

High Energy Physics - Theory · Physics 2019-10-01 Jin Qiao , Guang-Hua Ding , Qiang Wu , Tao Zhu , Anzhong Wang

Very few explicit inflationary scenarios are known to generate a large bispectrum of orthogonal shape. Dirac-Born-Infeld Galileon inflation, in which an induced gravity term is added to the DBI action, is one such model. We formulate it in…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Sebastien Renaux-Petel

Heavy scalar fields can undergo an instability during inflation as a result of their kinetic couplings with the inflaton. This is known as the geometrical destabilization of inflation, as it relies on the effect of the negative curvature of…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-07 Sebastian Garcia-Saenz , Sébastien Renaux-Petel , John Ronayne

The bispectrum of single-field inflationary trajectories in which the speed of sound of the inflationary trajectories $c_s$ is constant but not equal to the speed of light $c=1$ is explored. The trajectories are generated as random…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-30 Jonathan S. Horner , Carlo R. Contaldi

Using an effective field theory approach to inflation, we examine novel properties of the spectrum of inflationary tensor fluctuations, that arise when breaking some of the symmetries or requirements usually imposed on the dynamics of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Dario Cannone , Gianmassimo Tasinato , David Wands

We study the effective field theory of inflation, i.e. the most general theory describing the fluctuations around a quasi de Sitter background, in the case of single field models. The scalar mode can be eaten by the metric by going to…

High Energy Physics - Theory · Physics 2009-06-11 Clifford Cheung , Paolo Creminelli , A. Liam Fitzpatrick , Jared Kaplan , Leonardo Senatore