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Related papers: Accurately determining inflationary perturbations

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We present a technique, {\em the uniform asymptotic approximation}, to construct accurate analytical solutions of the linear perturbations of inflation after quantum effects of the early universe are taken into account, for which the…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-19 Tao Zhu , Anzhong Wang , Gerald Cleaver , Klaus Kirsten , Qin Sheng

In this short review, the predictions of inflation are presented and compared to the most recent measurements of the Cosmic Microwave Background (CMB) anisotropy. It is argued that inflation is compatible with these observations but that…

Astrophysics · Physics 2009-11-10 Jerome Martin

This article provides an introductory review of inflation and cosmological perturbation theory. I begin by motivating the need for an epoch of inflation during the early stages of the radiation dominated era, and describe how inflation is…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-08 L. Sriramkumar

We use the measurement of the cosmic microwave background taken during the MAXIMA-1 flight to estimate the bispectrum of cosmological perturbations. We propose an estimator for the bispectrum that is appropriate in the flat sky…

Cosmic microwave background (CMB) anisotropy may result from both scalar and tensor perturbations. For a sufficiently narrow range of angular scales, CMB perturbations can be characterized by four parameters. Results from the Cosmic…

Astrophysics · Physics 2009-10-22 Scott Dodelson , Lloyd Knox , Edward W. Kolb

Inflation creates both scalar (density) and tensor (gravity wave) metric perturbations. We find that the tensor mode contribution to the CMB anisotropy on large-angular scales can only exceed that of the scalar mode in models where the…

Astrophysics · Physics 2009-09-15 R. L. Davis , H. M. Hodges , G. F. Smoot , P. J. Steinhardt , M. S. Turner

Measuring spectral distortions (SDs) of the cosmic microwave background (CMB) will provide new constraints on previously unexplored scales of the primordial power spectrum, allowing us to extend the probed parameter space by several orders…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-03 Nils Schöneberg , Matteo Lucca , Deanna C. Hooper

Quantum fluctuations during inflation may be responsible for temperature anisotropies in the cosmic microwave background (CMB). Observations of CMB anisotropies can be used to falsify many currently popular models. In this paper we discuss…

Astrophysics · Physics 2009-10-30 Scott Dodelson , William H. Kinney , Edward W. Kolb

If an adiabatic density perturbation is responsible for large scale structure and the cmb anisotropy, its spectral index $n$ will be measured in the forseeable future with an accuracy $\Delta n\sim .01$. This is precisely the kind of…

High Energy Physics - Phenomenology · Physics 2016-09-06 David H. Lyth

Forthcoming cosmic microwave background experiments (CMB) will provide precise new tests of structure-formation theories. The geometry of the Universe may be determined robustly, and the classical cosmological parameters, such as the…

Astrophysics · Physics 2007-05-23 Marc Kamionkowski

We carry out numerical investigations of the perturbations in Nflation models where the mass spectrum is generated by random matrix theory. The tensor-to-scalar ratio and non-gaussianity are already known to take the single-field values,…

Astrophysics · Physics 2008-12-18 Soo A Kim , Andrew R Liddle

We derive a closed-form, analytical expression for the spectrum of long-wavelength density perturbations in inflationary models with two (or more) inflaton degrees of freedom that is valid in the slow-roll approximation. We illustrate…

Astrophysics · Physics 2009-09-15 V. F. Mukhanov , Paul J. Steinhardt

In inflationary models with minimal amount of gravity waves, the primordial power spectrum of density fluctuations, $A_S^2(k)$, together with the basic cosmological parameters, completely specify the predictions for the cosmic microwave…

Astrophysics · Physics 2009-10-31 Yun Wang , David N. Spergel , Michael A. Strauss

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

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

In principle, the tensor metric (gravity-wave) perturbations that arise in inflationary models can, beyond probing the underlying inflationary model, provide information about the Universe: ionization history, presence of a cosmological…

Astrophysics · Physics 2009-08-18 Michael S. Turner , Martin White , James E. Lidsey

Next-to-leading order expressions related to Stewart-Lyth inverse problem are used to determine the inflationary models with a tensorial power spectrum described by a scale-invariant spectral index. Beyond power-law inflation, solutions are…

Astrophysics · Physics 2016-08-16 César A. Terrero-Escalante , Eloy Ayón-Beato , Alberto A. García

With the advent of new missions to probe spectral distortions of the cosmic microwave background with unprecedented precision, the study of theoretical predictions of these signals becomes a promising avenue to test our description of the…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-31 Raul Henriquez-Ortiz , Jorge Mastache , Saul Ramos-Sanchez

Within the class of inflationary models, k-inflation represents the most general single field framework that can be associated with an effective quadratic action for the curvature perturbations and a varying speed of sound. The incoming…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-04 Jerome Martin , Christophe Ringeval , Vincent Vennin

We compute the power spectrum of curvature perturbations in stochastic inflation. This combines the distribution of first crossing times through the end-of-inflation surface, which has been previously studied, with the distribution of the…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-27 Kenta Ando , Vincent Vennin