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We explore the potential of the B-mode anisotropies of the Cosmic Microwave Background radiation (CMB) to constrain the shape of the primordial tensor power spectrum in a model-independent way. We expand possible perturbations to the…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-09 M. Farhang , A. Vafaei Sadr

We extend the standard theory of cosmological perturbations to homogeneous but anisotropic universes. We present an exhaustive computation for the case of a Bianchi I model, with a residual isotropy between two spatial dimensions, which is…

Astrophysics · Physics 2008-11-26 A. E. Gumrukcuoglu , Carlo R. Contaldi , Marco Peloso

A class of inflationary models that involve rapid bursts of particle productions predict observational signatures, such as bump-like features in the primordial scalar power spectrum. In this work, we analyze such models by comparing their…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-07 Suvedha Suresh Naik , Kazuyuki Furuuchi , Pravabati Chingangbam

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

The cosmic microwave background (CMB) radiation offers a unique avenue for exploring the early Universe's dynamics and evolution. In this paper, we delve into the fascinating realm of slow-roll inflation, contextualizing the primordial…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-01 D. Sidious , S. Arcari , N. Barbieri , L. Bazzanini , L. Caloni , G. Galloni , R. Impavido , M. Lattanzi , M. Lembo , A. Raffaelli , N. Raffuzzi , S. S. Sirletti

We propose a single field inflationary model by generalizing the inverse power law potential from the intermediate model. We study the implication of our model on the primordial anisotropy of cosmological microwave background radiation.…

High Energy Physics - Theory · Physics 2015-06-17 Zhun Lu

We show that the Planck 2015 and BICEP2/KECK measurements of the Cosmic Microwave Background (CMB) anisotropies provide together an information gain of 0.82 +- 0.13 bits on the reheating history over all slow-roll single-field models of…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-16 Jerome Martin , Christophe Ringeval , Vincent Vennin

The enormous red-shifting of the modes during the inflationary epoch suggests that physics at the very high energy scales may modify the primordial perturbation spectrum. Therefore, the measurements of the anisotropies in the Cosmic…

High Energy Physics - Theory · Physics 2015-06-26 S. Shankaranarayanan , L. Sriramkumar

We consider the linear perturbations for the single scalar field inflation model interacting with an additional triad of scalar fields. The background solutions of the three additional scalar fields depend on spatial coordinates with a…

General Relativity and Quantum Cosmology · Physics 2013-09-04 Seoktae Koh , Seyen Kouwn , O-Kab Kwon , Phillial Oh

Inflation is an early period of accelerated cosmic expansion, thought to be sourced by high energy physics. A key task today is to use the influx of increasingly precise observational data to constrain the plethora of inflationary models…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-05 Joseph Elliston

Adams et al. (1997b) have noted that according to our current understanding of the unification of fundamental interactions, there should have been phase transitions associated with spontaneous symmetry breaking {\em during} the inflationary…

Astrophysics · Physics 2008-11-26 Jose Barriga , Enrique Gaztanaga , Mario Santos , Subir Sarkar

Primordial magnetic fields are generated during inflation by considering actions that break the conformal invariance of the electromagnetic field. To break the conformal invariance, the electromagnetic fields are coupled either to the…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-22 Sagarika Tripathy , Debika Chowdhury , Rajeev Kumar Jain , L. Sriramkumar

We update the search for features in the Cosmic Microwave Background (CMB) power spectrum due to transient reductions in the speed of sound, using Planck 2015 CMB temperature and polarisation data. We enlarge the parameter space to much…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-25 Jesus Torrado , Bin Hu , Ana Achucarro

We investigate the presence of primordial oscillatory features in measurements of CMB anisotropies through a systematic comparison of phenomenological templates. Building upon previous searches for primordial features using Planck data, we…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-29 Antonio Raffaelli , Mario Ballardini , Nicola Barbieri

Non-Gaussianity in the distribution of inflationary perturbations, measurable in statistics of the cosmic microwave background (CMB) and large scale structure fluctuations, can be used to probe non-trivial initial quantum states for these…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Joyce Byun , Nishant Agarwal , Rachel Bean , Richard Holman

We calculate temperature anisotropies of the cosmic microwave background (CMB) for several initial power spectra of density perturbations with a built-in scale suggested by recent optical data on the spatial distribution of rich clusters of…

Astrophysics · Physics 2009-10-30 F. Atrio-Barandela , J. Einasto , S. Gottlöber , V. Müller , A. A. Starobinsky

Solid inflation is an effective field theory of inflation in which isotropy and homogeneity are accomplished via a specific combination of anisotropic sources (three scalar fields that individually break isotropy). This results in specific…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-11 Nicola Bartolo , Marco Peloso , Angelo Ricciardone , Caner Unal

Spectral distortion anisotropies of the cosmic microwave background (CMB) provide a new probe of the early Universe that can be accessed using traditional CMB imaging techniques. It is possible to compute the creation and evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-17 Jens Chluba , Sara Evangelista , Tom Daman , Geoff Vasil

We present three non-parametric Bayesian primordial reconstructions using Planck 2018 polarization data: linear spline primordial power spectrum reconstructions, cubic spline inflationary potential reconstructions and sharp-featured…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-20 Will J. Handley , Anthony N. Lasenby , Hiranya V. Peiris , Michael P. Hobson

The remarkable progress in cosmic microwave background (CMB) studies over past decade has led to the era of precision cosmology in striking agreement with the $\Lambda$CDM model. However, the lack of power in the CMB temperature…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-09 Asif Iqbal , Jayanti Prasad , Tarun Souradeep , Manzoor A. Malik
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