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Related papers: Tensor Microwave Anisotropies from a Stochastic Ma…

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We study how the presence of a background magnetic field, of intensity compatible with current observation constraints, affects the linear evolution of cosmological density perturbations at scales below the Hubble radius. The magnetic field…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-22 Massimiliano Lattanzi , Nakia Carlevaro , Giovanni Montani

We investigate the possibility that a heavy scalar field, whose mass exceeds the Hubble scale during inflation, could leave non-negligible signatures in the Cosmic Microwave Background (CMB) temperature anisotropy power spectrum through the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Ryo Saito , Masahiro Nakashima , Yu-ichi Takamizu , Jun'ichi Yokoyama

Stellar oscillations are key to unravelling stars' properties, such as their mass, radius and age. Amplitudes of acoustic modes in solar-like stars are intrinsically linked to their convective turbulent excitation source, which in turn is…

Solar and Stellar Astrophysics · Physics 2024-07-11 Leïla Bessila , Stéphane Mathis

Primordial magnetic fields could provide an explanation for the galactic magnetic fields observed today, in which case they may also leave interesting signals in the CMB and the small-scale matter power spectrum. We discuss how to…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-26 J. Richard Shaw , Antony Lewis

A model of Universe with a small eccentricity due to the presence of a magnetic field at the decoupling time (i.e. an Ellipsoidal Universe) has been recently proposed for the solution of the low quadrupole anomaly of the angular power…

Astrophysics · Physics 2008-12-18 Alessandro Gruppuso

We report a measurement of anisotropy in the cosmic microwave background radiation (CMBR) on 7-22 arcminute scales. Observations of 36 fields near the North Celestial Pole (NCP) were made at 31.7 and 14.5 GHz, using the 5.5-meter and…

Astrophysics · Physics 2007-05-23 E. M. Leitch , A. C. S. Readhead , T. J. Pearson , S. T. Myers , S. Gulkis , C. R. Lawrence

We show that the anisotropies of the astrophysical stochastic gravitational wave background in the mHz band have a strong dependence on the modelling of galactic and sub-galactic physics. We explore a wide range of self-consistent…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-08 Giulia Cusin , Irina Dvorkin , Cyril Pitrou , Jean-Philippe Uzan

This article explores the properties (amplitude and shape) of the angular power spectrum of the anisotropies of the astrophysical gravitational wave background (AGWB) focusing on the signatures of the astrophysical models describing…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-18 Giulia Cusin , Irina Dvorkin , Cyril Pitrou , Jean-Philippe Uzan

The natural outcome of theoretical calculations of microwave background anisotropy is the angular power spectrum ${\cal C}_\ell$ as a function of multipole number $\ell$. Experimental ${\cal C}_\ell$'s are needed for direct comparison.…

Astrophysics · Physics 2009-09-25 J. Richard Bond

Primordial statistical anisotropy is a key indicator to investigate early Universe models and has been probed by the cosmic microwave background (CMB) anisotropies. In this paper, we examine tensor-mode CMB fluctuations generated from…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-29 Maresuke Shiraishi , David F. Mota , Angelo Ricciardone , Frederico Arroja

We compute numerically the scalar- and tensor-mode induced Stokes parameters of the cosmic microwave background, by taking into account the basis rotation effects. It is found that the tensor contribution to the polarization power spectrum…

Astrophysics · Physics 2009-10-28 Ka Lok Ng , Kin-Wang Ng

We present the first statistical study of the anisotropy of the magnetic field turbulence in the solar wind between 1 and 200Hz, i.e. from proton to sub-electron scales. We consider 93 10-minute intervals of Cluster/STAFF measurements. We…

Space Physics · Physics 2017-10-18 Catherine Lacombe , Olga Alexandrova , Lorenzo Matteini

There has been much recent interest in studying anisotropies in the astrophysical gravitational-wave (GW) background, as these could provide us with interesting new information about galaxy clustering and large-scale structure. However,…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-29 Alexander C. Jenkins , Joseph D. Romano , Mairi Sakellariadou

The primordial magnetic field (PMF) can strongly affect the cosmic microwave background (CMB) power spectrum and the formation of large scale structure. In this presentation, we calculate the CMB temperature anisotropies generated by…

Astrophysics · Physics 2008-11-26 Dai G. Yamazaki , Kiyotomo Ichiki , Toshitaka Kajino , Grant J. Mathews

We study the effect of a possible helicity component of a primordial magnetic field on the tensor part of the cosmic microwave background temperature anisotropies and polarization. We give analytical approximations for the tensor…

Astrophysics · Physics 2009-11-07 Chiara Caprini , Ruth Durrer , Tina Kahniashvili

Cosmic string networks generate cosmological perturbations actively throughout the history of the universe. Thus, the string sourced anisotropy of the cosmic microwave background is not affected by Silk damping as much as the anisotropy…

Astrophysics · Physics 2010-04-15 Levon Pogosian , S. -H. Henry Tye , Ira Wasserman , Mark Wyman

Inflation generates gravitational waves, which may be observable in the low multipoles of the cosmic microwave background (cmb) anisotropy but only if the inflaton field variation is at least of order the Planck scale. Such a large…

High Energy Physics - Phenomenology · Physics 2009-10-28 David H. Lyth

We asses the contribution to the observed large scale anisotropy of the cosmic microwave background radiation, arising from both gravity waves as well as adiabatic density perturbations, generated by a common inflationary mechanism in the…

High Energy Physics - Phenomenology · Physics 2009-10-22 Tarun Souradeep , Varun Sahni

One of the major predictions of inflation is the existence of a stochastic background of cosmological gravitational waves (GW). These gravitational waves can induce significant temperature anisotropies in the Cosmic Microwave Background…

Astrophysics · Physics 2009-11-07 Alessandro Melchiorri , Carolina Odman

We consider anisotropies in the stochastic background of gravitational-waves (SBGW) arising from random fluctuations in the number of gravitational-wave sources. We first develop the general formalism which can be applied to different…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 S. Olmez , V. Mandic , X. Siemens
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