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Related papers: Inflationary Perturbations from Deformed CFT

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Inflation predicts the generation of cosmological perturbations. Usually, the power spectra for the scalar and tensor modes are calculated with help of the slow roll approximation. In the case of power law inflation an exact result is…

Astrophysics · Physics 2007-05-23 Dominik J. Schwarz , Jerome Martin

We extend the theory of cosmological perturbations to the case when the ``matter'' Lagrangian is an arbitrary function of the scalar field and its first derivatives. In particular, this extension provides a unified description of known…

High Energy Physics - Theory · Physics 2009-07-09 Jaume Garriga , V. F. Mukhanov

We derive the power spectrum $\mathcal P(k)$ of the density perturbations produced during inflation up to second-order corrections in the standard slow-roll approximation for an inflaton with more than one degree of freedom. We also present…

Astrophysics · Physics 2008-11-26 Jin-Ook Gong , Ewan D. Stewart

We analyse the dynamics of spinodal decomposition in inflationary cosmology using the closed time path formalism of out of equilibrium quantum field theory combined with the non-perturbative Hartree approximation. In addition to a general…

High Energy Physics - Phenomenology · Physics 2009-10-31 D. Cormier , R. Holman

We compute the spectrum of scalar and tensor metric perturbations generated, as amplified vacuum fluctuations, during an epoch of dilaton-driven inflation of the type occurring naturally in string cosmology. In the tensor case the…

High Energy Physics - Theory · Physics 2009-10-28 R. Brustein , M. Gasperini , M. Giovannini , V. F. Mukhanov , G. Veneziano

We develop the relation between de Sitter holography and inflation in detail, with particular attention to cosmic density perturbations. We set up the Hamilton-Jacobi formalism to present a systematic treatment of the logarithmic…

High Energy Physics - Theory · Physics 2010-02-03 Finn Larsen , Robert McNees

The holographic entropy bound is used to estimate the quantum-gravitational discreteness of inflationary perturbations. In the context of scalar inflaton perturbations produced during standard slow-roll inflation, but assuming that…

Astrophysics · Physics 2009-11-07 Craig J. Hogan

Using the de Sitter/CFT correspondence we describe a scenario of holographic inflation which is driven by a three dimensional boundary field theory. We find that inflationary constraints severely restrict the $\beta$--function, the…

High Energy Physics - Theory · Physics 2014-11-18 Edi Halyo

Scalar and tensor perturbations arising in an inflationary braneworld scenario driven by a single scalar field are considered, where the bulk on either side of the brane corresponds to Anti-de Sitter spaces with different cosmological…

Astrophysics · Physics 2009-11-07 Greg Huey , James E. Lidsey

The quantum-to-classical transition of inflationary perturbations remains an unresolved fundamental problem, and quantum decoherence is one of the promising solutions. By considering quantum perturbations during inflation as an open quantum…

General Relativity and Quantum Cosmology · Physics 2025-07-01 Zhongkai Wang , Yungui Gong

Inflation is often described through the dynamics of a scalar field, slow-rolling in a suitable potential. Ultimately, this inflaton must be identified as the expectation value of a quantum field, evolving in a quantum effective potential.…

High Energy Physics - Phenomenology · Physics 2021-05-11 Jens O. Andersen , Magdalena Eriksson , Anders Tranberg

We extend the formalism of stochastic inflation to the setup of non-attractor inflation with a sound speed $c_s$. We obtain the Langevin equations for the superhorizon perturbations and calculate the stochastic corrections to curvature…

High Energy Physics - Theory · Physics 2020-12-09 Hassan Firouzjahi , Amin Nassiri-Rad , Mahdiyar Noorbala

We analyse the spectrum of perturbations of the de Sitter space on the one hand, while on the other hand we compute the location of the poles in the Conformal Field Theory (CFT) propagator at the border. The coincidence is striking,…

High Energy Physics - Theory · Physics 2009-11-07 E. Abdalla , K. H. C. Castello-Branco , A. Lima-Santos

We investigate models of `intermediate' inflation, where the scale factor $a(t)$ grows as $a(t) = \exp (A t^f)$, $0 < f < 1$, $A$ constant. These solutions arise as exact analytic solutions for a given class of potentials for the inflaton…

Astrophysics · Physics 2009-12-30 John D Barrow , Andrew R Liddle

We compute the spectral distribution of the quantum fluctuations of the vacuum, amplified by inflation, after an arbitrary number of background transitions. Using a graphic representation of the process we find that the final spectrum can…

General Relativity and Quantum Cosmology · Physics 2009-11-07 G. De Risi , M. Gasperini

In this paper we analyze scalar gravitational perturbations on a Robertson-Walker background in the presence of multiple scalar fields that take values on a (geometrically non-trivial) field manifold during slow-roll inflation. For this…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Groot Nibbelink , B. J. W. van Tent

We continue the study of mild transient reductions in the speed of sound of the adiabatic mode during inflation, of their effect on the primordial power spectrum and bispectrum, and of their detectability in the Cosmic Microwave Background…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-19 Ana Achucarro , Vicente Atal , Bin Hu , Pablo Ortiz , Jesus Torrado

The standard calculation of the spectrum of density perturbations produced during inflation assumes that there is only one real dynamical degree of freedom during inflation. However, there is no reason to believe that this is actually the…

Astrophysics · Physics 2009-10-09 Misao Sasaki , Ewan D. Stewart

We build an inflationary model based on Degenerate Higher Order Scalar Tensor (DHOST) theories in a de Sitter background. We determine the scale-dependent power spectrum of curvature perturbations in these theories and we show that such a…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-25 Andrei Lazanu

It is conjectured that inflation, taking account of quantum gravity, leads to a discrete spectrum of cosmological perturbations, instead of the continuous Gaussian spectrum predicted by standard field theory in an unquantized background.…

Astrophysics · Physics 2009-11-10 Craig J. Hogan