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Primordial non-Gaussianity arising from inflationary models is a unique probe of non-trivial dynamics of the inflaton field and its interactions with other fields. Often when examining and constraining the scalar non-Gaussianity arising…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-17 Barnali Das , H. V. Ragavendra

We study the statistical descriptors for some cosmological inflationary models that allow us to get large levels of non-gaussianity and violations of statistical isotropy. Basically, we study two different class of models: a model that…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-05 Cesar A. Valenzuela-Toledo

We study the dynamics of scalar metric fluctuations in a non-perturbative variational formalism recently introduced, by which the dynamics of an geometrical scalar field $\theta$, describes the quantum geometrical effects on a Weylian-like…

General Relativity and Quantum Cosmology · Physics 2015-12-15 Mauricio Bellini

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

The most direct probe of non-Gaussian initial conditions has come from bispectrum measurements of temperature fluctuations in the Cosmic Microwave Background and of the matter and galaxy distribution at large scales. Such bispectrum…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 M. Liguori , E. Sefusatti , J. R. Fergusson , E. P. S. Shellard

We use holographic techniques to compute inflationary non-Gaussianities for general single-field inflation, including models with a non-trivial sound speed. In this holographic approach, the inflationary dynamics is captured by a relevant…

High Energy Physics - Theory · Physics 2016-12-14 Hiroshi Isono , Toshifumi Noumi , Gary Shiu , Sam S. C. Wong , Siyi Zhou

We study inflationary models that produce a nearly scale-invariant power spectrum while breaking scale invariance significantly in the bispectrum. Under most circumstances, such models are finely-tuned, as radiative corrections generically…

High Energy Physics - Theory · Physics 2015-06-05 Siavosh R. Behbahani , Daniel Green

Within the framework of loop quantum cosmology (LQC), we investigate the effect of inverse volume corrections on the low scale spontaneously broken supersymmetric (SB SUSY) and exponential inflationary potentials. The LQC modifications to…

General Relativity and Quantum Cosmology · Physics 2025-10-07 Farough Parvizi , Soma Heydari , Milad Solbi , Kayoomars Karami

We consider contributions to non-Gaussianity of the Cosmic Microwave Background (CMB) from remnants of post-inflationary phase transitions in the very early universe. Such signatures can optimistically be used to discover evidence of new…

Astrophysics · Physics 2010-01-11 Alessandra Silvestri , Mark Trodden

We compute the covariant three-point function near horizon-crossing for a system of slowly-rolling scalar fields during an inflationary epoch, allowing for an arbitrary field-space metric. We show explicitly how to compute its subsequent…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-10 Joseph Elliston , David Seery , Reza Tavakol

The cosmological primordial power spectrum is known to be one of the most promising observable to probe quantum gravity effects. In this article, we investigate how the tensor power spectrum is modified by Loop Quantum Gravity corrections.…

General Relativity and Quantum Cosmology · Physics 2010-04-06 J. Grain , T. Cailleteau , A. Barrau , A. Gorecki

Inflationary perturbations in multi-field theories can exhibit a transient tachyonic instability as a consequence of their non-trivial motion in the internal field space. When an effective single-field description is applicable, the…

High Energy Physics - Theory · Physics 2018-11-07 Sebastian Garcia-Saenz , Sébastien Renaux-Petel

A brief introduction to the gauge invariant classical and quantum theory of cosmological perturbations is given. The formalism is applied to inflationary Universe models and yields a consistent and unified description of the generation and…

Astrophysics · Physics 2007-05-23 R. Brandenberger , H. Feldman , V. Mukhanov

At the level of heuristic effective dynamics, we investigate the cosmological inflation with holonomy corrections of loop quantum cosmology (LQC) in the $k=0$ Friedmann-Robertson-Walker model with a single inflaton field subject to a simple…

General Relativity and Quantum Cosmology · Physics 2010-04-29 Dah-Wei Chiou , Kai Liu

We study cosmological perturbations generated from quantum fluctuations in multi-field inflationary scenarios in generalized Einstein theories, taking both adiabatic and isocurvature modes into account. In the slow-roll approximation,…

Astrophysics · Physics 2009-11-07 Alexei A. Starobinsky , Shinji Tsujikawa , Jun'ichi Yokoyama

We investigate the possible effects on the evolution of perturbations in the inflationary epoch due to short distance physics. We introduce a suitable non local action for the inflaton field, suggested by Noncommutative Geometry, and…

High Energy Physics - Theory · Physics 2009-11-07 Fedele Lizzi , Gianpiero Mangano , Gennaro Miele , Marco Peloso

We obtain the effective inflaton potential during slow roll inflation by including the one loop quantum corrections to the energy momentum tensor from scalar curvature and tensor perturbations as well as quantum fluctuations from light…

Astrophysics · Physics 2009-11-13 D. Boyanovsky , H. J. de Vega , N. G. Sanchez

We calculate the trispectrum T_\zeta of the primordial curvature perturbation \zeta, generated during a {\it slow-roll} inflationary epoch by considering a two-field quadratic model of inflation with {\it canonical} kinetic terms. We…

Astrophysics · Physics 2010-04-15 Yeinzon Rodriguez , Cesar A. Valenzuela-Toledo

Unifying the early-universe inflationary paradigm with late-time cosmic acceleration, while resolving the initial Big Bang singularity, remains one of the most profound challenges in modern cosmology. In this paper, we propose a…

General Relativity and Quantum Cosmology · Physics 2026-05-20 Zhiming Shuai , Xiangdong Zhang

Many models of inflation predict oscillatory features in the bispectrum of primordial fluctuations. Since it has been shown that primordial non-Gaussianity can lead to a scale-dependent halo bias, we investigate the effect of oscillations…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-20 Francis-Yan Cyr-Racine , Fabian Schmidt