English
Related papers

Related papers: Inflation with vector fields revisited: non-Gaussi…

200 papers

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

We study the power spectra and entropy of two-field warm inflationary scenario with canonical condition which is described by many-dimensional stochastic differential equations. The field perturbations are analytically calculated via a…

General Relativity and Quantum Cosmology · Physics 2019-03-12 Xi-Bin Li , Xiao-Gang Zheng , Jian-Yang Zhu

We develop an integral form for the bispectrum in general single-field inflation whose domain of validity includes models of inflation where the background evolution is not constrained to be slowly varying everywhere. Our integral form…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-18 Peter Adshead , Wayne Hu , V Miranda

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

During inflation, there is a preferred reference frame in which the expansion of the background spacetime is spatially isotropic. In contrast to Minkowski spacetime, observables can depend on the velocity of the system with respect to this…

General Relativity and Quantum Cosmology · Physics 2021-02-16 Tanguy Grall , Scott Melville

We discuss and clarify the validity of effective single field theories of inflation obtained by integrating out heavy degrees of freedom in the regime where adiabatic perturbations propagate with a suppressed speed of sound. We show by…

High Energy Physics - Theory · Physics 2012-12-17 Ana Achucarro , Vicente Atal , Sebastian Cespedes , Jinn-Ouk Gong , Gonzalo A. Palma , Subodh P. Patil

In this work we study slow-roll inflation for a vector-tensor model with massive vector fields non-minimally coupled to gravity. The model under consideration has arbitrary parameters for each geometrical coupling. Taking into account a…

General Relativity and Quantum Cosmology · Physics 2016-12-21 A. Oliveros

In earlier works, we studied the validity of Extended Effective Field Theory of Inflation (EEFToI) in the regime where initial conditions are set with dispersion relations $\omega^2 \propto k^6$. We had also evaluated and examined the power…

High Energy Physics - Theory · Physics 2023-04-28 Amjad Ashoorioon , Ghazal Geshnizjani , Hyung J. Kim

We derive parity-even graviton bispectra in the Effective Field Theory of Inflation (EFToI) to all orders in derivatives. Working in perturbation theory, we construct all cubic interactions that can contribute to tree-level graviton…

High Energy Physics - Theory · Physics 2022-11-09 Giovanni Cabass , David Stefanyszyn , Jakub Supeł , Ayngaran Thavanesan

We study a model of inflation with multiple pseudo-scalar fields coupled to a $U(1)$ gauge field through Chern-Simons interactions. Because of parity violating interactions, one polarization of the gauge field is amplified yielding to…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-12 Alireza Talebian , Seyed Ali Hosseini Mansoori , Hassan Firouzjahi

The effective field theory of inflation is a powerful tool for obtaining model independent predictions common to large classes of inflationary models. It requires only information about the symmetries broken during the inflationary era, and…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-11 Nicola Bartolo , Dario Cannone , Angelo Ricciardone , Gianmassimo Tasinato

The decay of massive particles during inflation generates characteristic signals in the squeezed limit of the primordial bispectrum. These signals are in particular distinctive in the regime of the quasi-single field inflation, where…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-08 Yi Wang , Yi-Peng Wu , Jun'ichi Yokoyama , Siyi Zhou

We provide a compact and unified treatment of power spectrum observables for the effective field theory (EFT) of inflation with the complete set of operators that lead to second-order equations of motion in metric perturbations in both…

High Energy Physics - Theory · Physics 2019-01-15 Hayato Motohashi , Wayne Hu

In this work, we construct an explicit string motivated example of three-field inflation in a related, yet distinct from, the recently discovered perturbative large volume scenario (pLVS). Contrary to the usual constructions, in this set…

High Energy Physics - Theory · Physics 2025-02-25 Vasileios Basiouris , Dibya Chakraborty

We consider a quasi-single field inflation model in which the inflaton interacts with a massive scalar field called the isocurvaton. Due to the breaking of time translational invariance by the inflaton background, these interactions induce…

High Energy Physics - Phenomenology · Physics 2018-06-27 Haipeng An , Michael McAneny , Alexander K. Ridgway , Mark B. Wise

A scale-invariant universe can have a period of accelerated expansion at early times: inflation. We use a frame-invariant approach to calculate inflationary observables in a scale invariant theory of gravity involving two scalar fields -…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-26 Pedro G. Ferreira , Christopher T. Hill , Johannes Noller , Graham G. Ross

We study the dynamics of a homogeneous, isotropic, and positively curved universe in the presence of a SU(2) gauge field or a triplet of mutually orthogonal vector fields. In the SU(2) case we use the previously known ansatz for the…

General Relativity and Quantum Cosmology · Physics 2021-10-11 Tomoaki Murata , Tsutomu Kobayashi

We introduce a simple string model of inflation, in which the inflaton field can take trans-Planckian values while driving a period of slow-roll inflation. This leads naturally to a realisation of large field inflation, inasmuch as the…

High Energy Physics - Theory · Physics 2015-03-13 M. Cicoli , C. P. Burgess , F. Quevedo

We compute the amplitude of the non-Gaussianities in inflationary models with multiple, uncoupled scalar fields. This calculation thus applies to all models of assisted inflation, including N-flation, where inflation is driven by multiple…

Astrophysics · Physics 2010-10-27 Thorsten Battefeld , Richard Easther

We discuss the hybrid inflation model where the inflaton field is nonminimally coupled to gravity. In the Jordan frame, the potential contains $\phi^4$ term as well as terms in the original hybrid inflation model. In our model, inflation…

High Energy Physics - Theory · Physics 2011-02-22 Seoktae Koh , Masato Minamitsuji
‹ Prev 1 4 5 6 7 8 10 Next ›