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Related papers: Distinguishing Causal Seeds from Inflation

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Chromo-Natural Inflation is the first worked example of a model of inflation in which slow-roll inflation is achieved by "magnetic drift" as opposed to Hubble friction. In this work, we give an account of the perturbations at linear order…

High Energy Physics - Theory · Physics 2015-06-15 Peter Adshead , Emil Martinec , Mark Wyman

We study the auto-correlation function of CMB polarization anisotropies and their cross correlation with temperature fluctuations as probe of the causal structure of the universe. Because polarization is generated at the last scattering…

Astrophysics · Physics 2016-08-30 David N. Spergel , Matias Zaldarriaga

We constrain cosmological models where the primordial perturbations have both an adiabatic and a (possibly correlated) cold dark matter (CDM) or baryon isocurvature component. We use both a phenomenological approach, where the primordial…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-09 Jussi Valiviita , Matti Savelainen , Marianne Talvitie , Hannu Kurki-Suonio , Stanislav Rusak

Quantum field theory, which is generally used to describe the origin of large-scale gravitational perturbations during cosmic inflation, has been shown to omit an important physical effect in curved space-time, the nonlocal entanglement…

General Relativity and Quantum Cosmology · Physics 2022-04-01 Craig Hogan

We consider anisotropies in the Cosmic Microwave Background (CMB) generated by spatially limited seeds; these objects could correspond to relics of high energy symmetry breaking in the early universe. It is shown how the CMB perturbation…

Astrophysics · Physics 2009-09-25 Carlo Baccigalupi

We analyze the behavior of linear perturbations in vector inflation. In contrast to the scalar field inflation, the linearized theory with vector fields contains couplings between scalar, vector and tensor modes. The perturbations decouple…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-30 Alexey Golovnev , Vitaly Vanchurin

Measurements of CMB anisotropy and, more recently, polarization have played a very important role in cosmology. Besides precise determination of various parameters of the `standard' cosmological model, observations have also established…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-02 Tarun Souradeep

Fluctuations in the intensity and polarization of the cosmic microwave background (CMB) and the large-scale distribution of matter in the universe each contain clues about the nature of the earliest moments of time. The next generation of…

We analyze an inflationary model in which part of the power in density perturbations arises due to particle production. The amount of particle production is modulated by an auxiliary field. Given an initial gradient for the auxiliary field,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Guido D'Amico , Roberto Gobbetti , Matthew Kleban , Marjorie Schillo

In multiple inflation scenario having two inflations with an intermediate matter-dominated phase, the power spectrum is estimated to be enhanced on scales smaller than the horizon size at the beginning of the second inflation, $k > k_{\rm…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-16 Gimin Bae , Sungjae Bae , Seungho Choe , Seo Hyun Lee , Jungwon Lim , Heeseung Zoe

A scenario with two subsequent periods of inflationary expansion in the very early universe is examined. The model is based on a potential motivated by symmetries being found in field theory at high energy. For various parameter sets of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-13 Simon Schettler , Jurgen Schaffner-Bielich

We propose that several of the anomalies that have been observed at large angular scales in the CMB have a common origin in a cosmic bounce that took place before the inflationary era. The bounce introduces a new physical scale in the…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-27 Ivan Agullo , Dimitrios Kranas , V. Sreenath

In this letter, we propose a model of inflationary cosmology with a bounce preceded and study its primordial curvature perturbations. Our model gives rise to a primordial power spectrum with a feature of oscillation on large scales compared…

Astrophysics · Physics 2009-02-02 Yi-Fu Cai , Tao-tao Qiu , Jun-Qing Xia , Xinmin Zhang

A brief account is given of large-scale structure modelling based on the assumption that the initial perturbations arise from inflation. A recap is made of the implications of inflation for large-scale structure; under the widely applicable…

Astrophysics · Physics 2007-05-23 Andrew R Liddle

We develop a cosmological model where primordial inflation is driven by a 'solid', defined as a system of three derivatively coupled scalar fields obeying certain symmetries and spontaneously breaking a certain subgroup of these. The…

High Energy Physics - Theory · Physics 2015-06-11 Solomon Endlich , Alberto Nicolis , Junpu Wang

Inflation, a period of exponential expansion in the early Universe, is considered an important part of the standard $\Lambda$CDM cosmological model, and plays a crucial role in explaining a wide range of current observations. The standard…

General Relativity and Quantum Cosmology · Physics 2023-12-08 Maria Pia Piccirilli , Gabriel Leon

Comparison of theobservedanisotropy with that predicted iadiabaticDM models suggest that much of thserved signal may be due to long wavelenh gravitational waves. In inflationary models this requires the generation of tensor fluctuations to…

High Energy Physics - Phenomenology · Physics 2007-05-23 Lawrence M. Krauss

Different inflationary models predict oscillatory features in the primordial power spectrum. These can leave an imprint on both the cosmic microwave background (CMB) and the large-scale structure (LSS) of our Universe, that can be searched…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-15 Chenxiao Zeng , Ely D. Kovetz , Xuelei Chen , Yan Gong , Julian B. Muñoz , Marc Kamionkowski

The observed baryon asymmetry, as well as potentially an asymmetry in the dark matter sector, can be produced through dissipative particle production during inflation. A distinctive feature of this mechanism is the generation of matter…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-29 Mar Bastero-Gil , Arjun Berera , Rudnei O. Ramos , Joao G. Rosa

Power spectra always play an important role in the theory of inflation. In particular, the ability to reproduce the galaxy matter power spectrum and the CMB temperature angular power spectrum coefficients to high accuracy is often…

General Relativity and Quantum Cosmology · Physics 2019-11-01 Herbert W. Hamber , Lu Heng Sunny Yu