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Related papers: Non-Gaussianity from Axion Monodromy Inflation

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We develop a supersymmetric bi-axion model of high-scale inflation coupled to supergravity, in which the axionic structure originates from, and is protected by, gauge symmetry in an extra dimension. While local supersymmetry (SUSY) is…

High Energy Physics - Phenomenology · Physics 2021-07-01 Kaustubh Deshpande , Raman Sundrum

Although cosmological observations suggest that the fluctuations of seed fields are almost Gaussian, the possibility of a small deviation of their fields from Gaussianity is widely discussed. Theoretically, there exist numerous inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-21 Maresuke Shiraishi

We investigate inflationary scenarios driven by a class of potentials which are similar in form to those that arise in certain minimal supersymmetric extensions of the standard model. We find that these potentials allow a brief period of…

Inflation in a five-dimensional brane world model with two boundary branes is studied. We make use of the moduli space approximation whereby the low energy theory reduces to a four-dimensional biscalar-tensor gravity plus a minimally…

We compute the leading order contribution to the four-point function of the primordial curvature perturbation in a class of single field models where the inflationary Lagrangian is a general function of the inflaton and its first…

High Energy Physics - Theory · Physics 2008-12-04 Xingang Chen , Min-xin Huang , Gary Shiu

We show that a moduli space of the form predicted by string theory, lifted by supersymmetry breaking, gives rise to successful inflation for large regions of parameter space without any modification or fine tuning. This natural realization…

High Energy Physics - Phenomenology · Physics 2009-11-10 Kenji Kadota , Ewan D. Stewart

We present a detailed study of the trispectrum of the curvature perturbation generated within a stable, well defined and predictive theory which comprises an inflationary phase. In this model the usual shift symmetry is enhanced up to the…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-18 Frederico Arroja , Nicola Bartolo , Emanuela Dimastrogiovanni , Matteo Fasiello

The spectrum of primordial fluctuations from inflation can be obtained using a mathematically controlled, and systematically extendable, uniform approximation. Closed-form expressions for power spectra and spectral indices may be found…

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

After simplifying and improving the non-Gaussian formalism we developed in previous work, we derive a quantitative expression for the three-point correlator (bispectrum) of the curvature perturbation in general multiple-field inflation…

Astrophysics · Physics 2008-11-26 G. I. Rigopoulos , E. P. S. Shellard , B. J. W. van Tent

The hierarchy of fermion masses in the standard model may arise via the breaking of discrete gauge symmetries. The renormalizable interactions of the flavor-symmetry-breaking potential can have accidental global symmetries that are…

High Energy Physics - Phenomenology · Physics 2016-01-06 Christopher D. Carone , Raymundo Ramos , Zhen Wang

In this work we present an inflationary mechanism based on fluid dynamics. Starting with the action for a single barotropic perfect fluid, we outline the procedure to calculate the power spectrum and the bispectrum of the curvature…

High Energy Physics - Theory · Physics 2015-06-16 Xingang Chen , Hassan Firouzjahi , Mohammad Hossein Namjoo , Misao Sasaki

The presence of axion strings in the Universe after recombination can leave an imprint on the polarization pattern of the cosmic microwave background radiation through the phenomenon of axion-string-induced birefringence via the hyperlight…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-19 Ray Hagimoto , Andrew J. Long

We analyze the power spectrum and the bispectrum of BOSS galaxy-clustering data using the prediction from the Effective Field Theory of Large-Scale Structure at one-loop order for $\textit{both}$ the power spectrum $\textit{and}$ the…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-08 Guido D'Amico , Matthew Lewandowski , Leonardo Senatore , Pierre Zhang

A class of non-canonical inflationary models is identified, where the leading-order contribution to the non-Gaussianity of the curvature perturbation is determined by the sound speed of the fluctuations in the inflaton field. Included in…

High Energy Physics - Theory · Physics 2008-11-26 Ian Huston , James E. Lidsey , Steven Thomas , John Ward

Assuming a slow-roll inflationary model where conformal invariance of the Maxwell action is broken via a non-minimal kinetic coupling term, we investigate the non-Gaussian three-point cross-correlation function between the primordial…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-08 Arko Bhaumik , Supratik Pal

The theory and methodology is developed to compute the bispectrum in warm inflation, leading to results for the non-linearity parameter and the shape of the bispectrum. Particular attention is paid to the study of the bispectrum in the…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-10 Mar Bastero-Gil , Arjun Berera , Ian G. Moss , Rudnei O. Ramos

We discuss phenomenological aspects of no-scale supergravity inflationary models motivated by compactified string models, in which the inflaton may be identified either as a K\"ahler modulus or an untwisted matter field, focusing on models…

High Energy Physics - Phenomenology · Physics 2015-10-07 John Ellis , Marcos A. G. Garcia , Dimitri V. Nanopoulos , Keith A. Olive

We carry out a thorough numerical examination of field theory monodromy inflation at strong coupling. We perform an MCMC analysis using a Gaussian likelihood, fitting multiparameter models using CMB constraints on the spectral index and the…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-12 Edmund J. Copeland , Francesc Cunillera , Adam Moss , Antonio Padilla

We propose the generic no-scale inflation inspired from string theory compactifications. We consider the K\"ahler potentials with an inflaton field $\varphi$, as well as one, two, and three K\"ahler moduli. Also, we consider the…

High Energy Physics - Phenomenology · Physics 2022-08-09 Lina Wu , Tianjun Li