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Related papers: Statistical Anisotropy and the Vector Curvaton Par…

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We present a review of vector field models of inflation and, in particular, of the statistical anisotropy and non-Gaussianity predictions of models with SU(2) vector multiplets. Non-Abelian gauge groups introduce a richer amount of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Emanuela Dimastrogiovanni , Nicola Bartolo , Sabino Matarrese , Antonio Riotto

A coherent field over the entire universe is an attractive picture in studying the dark sector of the universe. The misalignment mechanism, which relies on inflation to achieve homogeneousness of the field, is a popular mechanism for…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-11 Kunio Kaneta , Hye-Sung Lee , Jiheon Lee , Jaeok Yi

We revisit the dynamics of the axial coupling between many N-flatons and an Abelian gauge field, with special attention to its statistically anisotropic signal. The anisotropic power spectrum of curvature perturbations associated to the…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-02 Federico R. Urban

We study curvature perturbations in the anisotropic inflationary model with a complex scalar field charged under a $U(1)$ gauge field in Bianchi I universe. Due to Abelian Higgs mechanism, the gauge field receives an additional longitudinal…

High Energy Physics - Theory · Physics 2015-06-12 Razieh Emami , Hassan Firouzjahi

We study the statistics of the primordial power spectrum in models where massless gauge vectors are coupled to the inflaton, paying special attention to observational implications of having fundamental or effective horizons embedded in a…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-07 Mikjel Thorsrud , Federico R. Urban , David F. Mota

Recent observations opened up a new window on the inflationary model building. As it was firstly reported by the WMAP data, there may be some indications of statistical anisotropy on the CMB map, although the statistical significance of…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-06 Razieh Emami

If the waterfall field of hybrid inflation couples to a U(1) gauge field, the waterfall can generate a statistically anisotropic contribution to the curvature perturbation. We investigate this possibility, generalising in several directions…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-01 David H. Lyth , Mindaugas Karciauskas

The cosmological curvature perturbation may be generated when some `curvaton' field, different from the inflaton, oscillates in a background of unperturbed radiation. In its simplest form the curvaton paradigm requires the Hubble parameter…

High Energy Physics - Theory · Physics 2008-11-26 David H. Lyth

A quantum theory of massive Abelian vector bosons with non-minimal couplings to gravity has been studied within an evolving, isotropic, and homogeneous gravitational background. The vectors may play a role of dark matter if stabilizing…

High Energy Physics - Phenomenology · Physics 2024-11-12 Bohdan Grzadkowski , Anna Socha

Inflationary models including vector fields have attracted a great deal of attention over the past decade. Such an interest owes to the fact that they might contribute to, or even be fully responsible for, the curvature perturbation…

General Relativity and Quantum Cosmology · Physics 2023-04-17 Juan C. Bueno-Sánchez , J. Bayron Orjuela-Quintana , César A. Valenzuela-Toledo

We study both the background evolution and cosmological perturbations of anisotropic inflationary models supported by coupled scalar and vector fields. The models we study preserve the U(1) gauge symmetry associated with the vector field,…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-29 Burak Himmetoglu

Anisotropic inflation is an interesting model with an U(1) gauge field and it predicts the statistical anisotropy of the curvature perturbation characterized by a parameter $g_*$. However, we find that the background gauge field does not…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-14 Tomohiro Fujita , Ippei Obata

The curvaton paradigm can realise a part of or all the observed curvature perturbation. Based on the stochastic formalism of inflation and closed-form exact distributions therein, the distribution of the curvature perturbation is presented…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-26 Koki Tokeshi

The small and large scale problem of various passive vector models with anisotropic forcing is considered by solving exactly the equation for the pair correlation function. Emphasis is placed in the phenomena of anomalous scaling and the…

Chaotic Dynamics · Physics 2013-05-29 Heikki Arponen

We construct a model of hidden massive vector boson dark matter as a homogeneous coherent oscillation in the entire universe without any dangerous instability. We make use of a particular form of the vector boson coupling to a scalar field…

High Energy Physics - Phenomenology · Physics 2023-03-08 Kazunori Nakayama

We extend the curvaton scenario presented by Erickcek et al. (2008, 2009), to explain how the even-odd multipole asymmetry of the Cosmic Microwave Background (CMB) (also called parity asymmetry, (Kim & Naselsky 2010)) and power anisotropies…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-29 Hao Liu , Anne Mette Frejsel , Pavel Naselsky

Various extensions of standard inflationary models have been proposed recently by adding vector fields. Because they are generally motivated by large-scale anomalies, and the possibility of statistical anisotropy of primordial fluctuations,…

High Energy Physics - Theory · Physics 2014-12-02 Pierre Fleury , Juan P. Beltran Almeida , Cyril Pitrou , Jean-Philippe Uzan

Vector fields in the expanding Universe are considered within the multidimensional theory of General Relativity. Vector fields in general relativity form a three-parametric variety. Our consideration includes the fields with a nonzero…

General Relativity and Quantum Cosmology · Physics 2015-05-28 Boris E. Meierovich

The so-called curvaton mechanism --a way to convert isocurvature perturbations into adiabatic ones-- is investigated both analytically and numerically in a pre-big bang scenario where the role of the curvaton is played by a sufficiently…

High Energy Physics - Phenomenology · Physics 2009-11-07 V. Bozza , M. Gasperini , M. Giovannini , G. Veneziano

The curvaton scenario for the generation of the cosmological curvature perturbation on large scales represents an alternative to the standard slow-roll scenario of inflation in which the observed density perturbations are due to…

Astrophysics · Physics 2008-12-18 N. Bartolo , S. Matarrese , A. Riotto , A. Vaihkonen