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Related papers: Scale-dependent bias from multiple-field inflation

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We evaluate the dimensionless non-Gaussianity parameter $h_{_{\rm NL}}$, that characterizes the amplitude of the tensor bispectrum, numerically for a class of two field inflationary models such as double inflation, hybrid inflation and…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-26 Rathul Nath Raveendran , L. Sriramkumar

We investigate the stochastic dynamics of the long wavelength modes of a generic light scalar field that during inflation is coupled to another scalar field. The coupling plays an important role for the fluctuation of the field amplitude…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Juan C. Bueno Sánchez , Kari Enqvist

The Higgs field is an attractive candidate for the inflaton because it is an observationally confirmed fundamental scalar field. Importantly, it can be modeled by the most general renormalizable scalar potential. However, if the classical…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-29 Martin Bojowald , Suddhasattwa Brahma , Sean Crowe , Ding Ding , Joseph McCracken

Although the paradigm of inflation has been extensively studied to demonstrate how macroscopic inhomogeneities in our universe originate from quantum fluctuations, most of the established literature ignores the crucial role that…

High Energy Physics - Theory · Physics 2022-11-30 Suddhasattwa Brahma , Arjun Berera , Jaime Calderón-Figueroa

We show that a perturbed inflationary spacetime, driven by a canonical single scalar field, is invariant under a special class of coordinate transformations together with a field reparametrization of the curvature perturbation in co-moving…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-15 Rafael Bravo , Sander Mooij , Gonzalo A. Palma , Bastián Pradenas

Multi-field inflation can be inherently non-predictive, with the exception of models with strong attractors. In this work, we focus on models with multiple scalar fields that are non-minimally coupled to the space-time Ricci curvature…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-18 Perseas Christodoulidis , Robert Rosati , Evangelos I. Sfakianakis

We consider cosmological inflation generated by a scalar field slowly rolling off from a de Sitter maximum of its potential. The models belong to the class of hilltop models and represent the most general model of this kind in which the…

General Relativity and Quantum Cosmology · Physics 2016-09-05 Mariano Cadoni , Edgardo Franzin , Salvatore Mignemi

We consider a possibility that one of the flat directions in the minimal supersymmetric standard model plays the role of the inflaton field and realizes large-field inflation. This is achieved by introducing a generalized shift symmetry on…

High Energy Physics - Phenomenology · Physics 2015-06-19 Shinta Kasuya , Fuminobu Takahashi

A new class of gravity-matter model defined with an independent non-Riemannian volume form is studied, in the second order formalism. The action has a global scale invariance symmetry, which can be broken by the equation of motion of the…

General Relativity and Quantum Cosmology · Physics 2019-05-22 David Benisty , Eduardo I. Guendelman

We apply the holographic principle during the inflationary stage of our universe. Where necessary, we illustrate the analysis in the case of new and extended inflation which, together, typify generic models of inflation. We find that in the…

High Energy Physics - Theory · Physics 2009-10-31 S. Kalyana Rama , Tapobrata Sarkar

In the present work, we study slow-roll inflation in scalar-tensor gravity theories in the presence of both the non-minimal coupling between the scalar field and curvature, and the Galileon self-interaction of the scalar field. Furthermore,…

General Relativity and Quantum Cosmology · Physics 2021-11-11 Matías López , Giovanni Otalora , Nelson Videla

Inflationary cosmology proposes that the early Universe undergoes accelerated expansion, driven, in simple scenarios, by a single scalar field, or inflaton. The form of the inflaton potential determines the initial spectra of density…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-21 Richard Easther , Benedict Bahr-Kalus , David Parkinson

We present a unified framework that simultaneously addresses the dynamics of early-time cosmic inflation and late-time cosmic acceleration within the context of a single scalar field non-minimally coupled to gravity. By employing an…

General Relativity and Quantum Cosmology · Physics 2025-10-27 Seong Chan Park

Inflection point inflation generically includes a deviation from slow-roll when the inflaton approaches the inflection point. Such deviations are shown to be generated by transitions between singular trajectories. The effects on the power…

High Energy Physics - Theory · Physics 2013-07-22 Sean Downes , Bhaskar Dutta

We study the general relation between the power spectrum and the squeezed limit of the bispectrum of the comoving curvature perturbation produced during single-field slow-roll inflation when the initial state is a general vacuum. Assuming…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Jinn-Ouk Gong , Misao Sasaki

Forthcoming missions probing the absolute intensity of the CMB are expected to be able to measure spectral distortions, which are deviations from its blackbody distribution. As cosmic inflation can induce spectral distortions, these…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-22 Alexander Baur , Marcos A. G. Garcia , Raul Henriquez-Ortiz , Mauricio Hernandez-Neri , Saul Ramos-Sanchez

By a careful implementation of gauge transformations involving long-wavelength modes, we show that a variety of effects involving squeezed bispectrum configurations, for which one Fourier mode is much shorter than the other two, cannot be…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-03 Sabino Matarrese , Luigi Pilo , Rocco Rollo

Inflation is nowadays a well-established paradigm consistent with all the observations. The precise nature of the inflaton is however unknown and its role could be played by any candidate able to imitate a scalar condensate in the slow-roll…

High Energy Physics - Phenomenology · Physics 2015-09-02 Javier Rubio

We construct a model of inflation based on a low-energy effective theory of spontaneously broken global scale invariance. This provides a shift symmetry that protects the inflaton potential from quantum corrections. Since the underlying…

High Energy Physics - Theory · Physics 2014-10-22 Csaba Csaki , Nemanja Kaloper , Javi Serra , John Terning

We investigate the inflationary expansion of the universe induced by higher curvature corrections in M-theory. The inflationary evolution of the geometry is discussed in ref.[1], thus we succeed to analyse metric perturbations around the…

High Energy Physics - Theory · Physics 2020-09-15 Kazuho Hiraga , Yoshifumi Hyakutake