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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 consider the pertubative consistency of inflationary models with features with effective field theory methods. By estimating the size of one-loop contributions to the three-point function, we find the energy scale where their…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-02 Dario Cannone , Nicola Bartolo , Sabino Matarrese

We generalize the Effective Field Theory of Inflation to include additional light scalar degrees of freedom that are in their vacuum at the time the modes of interest are crossing the horizon. In order to make the scalars light in a natural…

High Energy Physics - Theory · Physics 2015-05-19 Leonardo Senatore , Matias Zaldarriaga

Solid inflation is a cosmological model where inflation is driven by fields which enter the Lagrangian in the same way as body coordinates of a solid matter enter the equation of state, spontaneously breaking spatial translational and…

General Relativity and Quantum Cosmology · Physics 2019-03-18 Peter Mészáros

In the framework of superstring compactifications with N=1 supersymmetry spontaneously broken, (by either geometrical fluxes, branes or else), we show the existence of new inflationary solutions. The time-trajectory of the scale factor of…

High Energy Physics - Theory · Physics 2008-11-26 Costas Kounnas , Herve Partouche

We compute correlation functions of the primordial density perturbations when they couple to a gapless, strongly coupled sector of spectator fields -- ``unparticles" -- during inflation. We first derive a four-point function of conformally…

High Energy Physics - Theory · Physics 2026-04-21 Guilherme L. Pimentel , Chen Yang

We present a new class of two-field inflationary attractor models, known as `shift-symmetric orbital inflation', whose behaviour is strongly multi-field but whose predictions are remarkably close to those of single-field inflation. In these…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-29 Ana Achúcarro , Edmund J. Copeland , Oksana Iarygina , Gonzalo A. Palma , Dong-Gang Wang , Yvette Welling

We study the renormalized energy-momentum tensor (EMT) of the inflaton fluctuations in rigid space-times during the slow-rollover regime for chaotic inflation with a mass term. We use dimensional regularization with adiabatic subtraction…

General Relativity and Quantum Cosmology · Physics 2008-11-26 F. Finelli , G. Marozzi , G. P. Vacca , G. Venturi

We compute the large scalar four-point correlation functions in general single field inflation models, where the inflaton Lagrangian is an arbitrary function of the inflaton and its first derivative. We find that the leading order…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-28 Xingang Chen , Bin Hu , Min-xin Huang , Gary Shiu , Yi Wang

The observed power spectrum of the cosmic microwave background (CMB) is consistent with inflationary cosmology, which predicts a nearly scale-invariant power spectrum of quantum fluctuations of the inflaton field as they exit the Hubble…

High Energy Physics - Theory · Physics 2007-05-23 Leonard Parker

We consider the torsional completion of gravity with spinor and scalar fields: we show how in this environment conditions of extreme symmetry or specific approximations imply the scalar field to be constant, so that slow-roll takes place…

General Relativity and Quantum Cosmology · Physics 2017-07-07 Luca Fabbri

We present some features of early universe cosmology in terms of Hankel functions index ($\nu$). Actually, the recent data from observational cosmology indicate that our universe was nearly de Sitter space-time in the early times which…

High Energy Physics - Theory · Physics 2018-04-06 E. Yusofi , M. Mohsenzadeh

Developing our understanding of how correlations evolve during inflation is crucial if we are to extract information about the early Universe from our late-time observables. To that end, we revisit the time evolution of scalar field…

High Energy Physics - Theory · Physics 2021-02-16 Sebastian Cespedes , Anne-Christine Davis , Scott Melville

In order to study the effect of the anti de Sitter/ conformal field theory correspondence (AdS/CFT) on the primordial inflationary era, we consider a universe filled with a tachyon field in a slow-roll regime. In this context, the…

High Energy Physics - Theory · Physics 2016-12-14 Zahra Bouabdallaoui , Ahmed Errahmani , Mariam Bouhmadi-Lopez , Taoufik Ouali

We study the asymmetric primordial fluctuations in a model of inflation in which translational invariance is broken by a domain wall. We calculate the corrections to the power spectrum of curvature perturbations; they are anisotropic and…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-02 Sadra Jazayeri , Yashar Akrami , Hassan Firouzjahi , Adam R. Solomon , Yi Wang

We propose a new scenario for early cosmology, where an inflationary de Sitter phase is obtained with a ghost condensate. The transition to radiation dominance is triggered by the ghost itself, without any slow-roll potential. Density…

High Energy Physics - Theory · Physics 2011-05-05 Nima Arkani-Hamed , Paolo Creminelli , Shinji Mukohyama , Matias Zaldarriaga

If the beginning of inflation is defined at the moment when the vacuum energy of the inflaton starts to dominate, the energy density of the other fields at that moment is (by definition) comparable to the inflaton. Although the fraction…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-10 Kazunori Kohri , Chia-Min Lin , Tomohiro Matsuda

Scalar fields provide attractive modifications of pre-BBN cosmology, which have interesting implications for dark matter abundances. We analyse the effect of these modifications on the number of e-foldings between horizon exit of CMB modes…

High Energy Physics - Phenomenology · Physics 2018-06-20 Anshuman Maharana , Ivonne Zavala

In the first part of this paper, we outline the construction of an inflationary cosmology in the framework where inflation is described by a universally evolving scalar field, with the Lagrangian ${\cal L}_\phi=-{1/2}(\partial\phi)^2…

Astrophysics · Physics 2009-12-15 Ishwaree P. Neupane , Christoph Scherer

We approach the cosmological inflation thought symmetries of differential equations. We consider the general inflaton field in a homogeneous Friedmann--Lema\^{\i}tre--Robertson--Walker spacetime and with the use of conformal transformations…

General Relativity and Quantum Cosmology · Physics 2019-10-02 Andronikos Paliathanasis