English
Related papers

Related papers: Microwave Background Anisotropies from Alfven wave…

200 papers

We have investigated the cosmic microwave background (CMB) anisotropy in closed multiply connected universes (flat and hyperbolic) with low matter density. We show that the COBE constraints on these low matter density models with…

Astrophysics · Physics 2016-08-30 Kaiki Taro Inoue

We investigate a possible asymmetry in the statistical properties of the cosmic microwave background temperature field and to do so we construct an estimator aiming at detecting a dipolar modulation. Such a modulation is found to induce…

Astrophysics · Physics 2009-11-10 Simon Prunet , Jean-Philippe Uzan , Francis Bernardeau , Tristan Brunier

We suggest that the cosmic microwave background (CMB) temperature correlation function C(theta) as a function of angle provides a direct connection between experimental data and the fundamental cosmological quantities. The evolution of…

Astrophysics · Physics 2009-10-31 Sergei Bashinsky , Edmund Bertschinger

We show that significant anisotropy in electromagnetic propagation generates a distinctive signature in the microwave background. The anisotropy may be determined by looking at the cross correlator of the $E$-mode and $B$-mode polarisation…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Nathan F. Lepora

The cosmic microwave background (CMB) temperature anisotropies from primordial magnetic fields are studied. In addition to the known passive and the compensated mode we discuss an inflationary magnetic mode in the curvature perturbation,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Camille Bonvin , Chiara Caprini , Ruth Durrer

I present a briefly summary of the current status of inflationary models versus topological defects scenarios, as the mechanisms which could have induced the initial density perturbations, which left an imprint on the cosmic microwave…

Astrophysics · Physics 2007-05-23 Mairi Sakellariadou

Most of the analysis of the Cosmic Microwave Background relies on the assumption of statistical isotropy. However, given some recent evidence pointing against isotropy, as for instance the observed alignment of different multipoles on large…

Astrophysics · Physics 2007-11-12 A. E. Gumrukcuoglu , Carlo R. Contaldi , Marco Peloso

Using a set of cosmological hydro-dynamical simulations, we constrained the properties of primordial magnetic fields by studying their impact on the formation and evolution of dwarf galaxies. We performed a large set of simulations (8 dark…

Astrophysics of Galaxies · Physics 2020-11-04 Mahsa Sanati , Yves Revaz , Jennifer Schober , Kerstin E. Kunze , Pascale Jablonka

We derive an expression for the angular power spectrum of cosmic microwave background anisotropies due to gravity waves generated by a stochastic magnetic field and compare the result with current observations; we take into account the…

Astrophysics · Physics 2016-08-30 R. Durrer , P. G. Ferreira , T. Kahniashvili

We discuss the cosmological evolution of matter sources with small anisotropic pressures. This includes electric and magnetic fields, collisionless relativistic particles, gravitons, antisymmetric axion fields in low-energy string…

General Relativity and Quantum Cosmology · Physics 2007-05-23 John D. Barrow

The Cosmic Microwave Background (CMB) is a relict of the early universe. Its perfect 2.725K blackbody spectrum demonstrates that the universe underwent a hot, ionized early phase; its anisotropy (about 80 \mu K rms) provides strong evidence…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 Paolo de Bernardis , Silvia Masi

The existence of large-scale anisotropy can not be ruled out by the cosmic microwave background (CMB) radiation. Over the years, several models have been proposed in the context of anisotropic inflation to account for CMB's cold spot and…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-15 Sourav Pal , Debaprasad Maity , Tuan Q. Do

We give a brief review of the physics of acoustic oscillations in Cosmic Microwave Background (CMB) anisotropies. As an example of the impact of their detection in cosmology, we show how the present data on CMB angular power spectrum on…

Astrophysics · Physics 2015-06-24 C. Baccigalupi , A. Balbi , S. Matarrese , F. Perrotta , N. Vittorio

We study a homogeneous and nearly-isotropic Universe permeated by a homogeneous magnetic field. Together with an isotropic fluid, the homogeneous magnetic field, which is the primary source of anisotropy, leads to a plane-symmetric Bianchi…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-11 Julian Adamek , Ruth Durrer , Elisa Fenu , Marc Vonlanthen

The cosmic microwave background (CMB), the relic radiation from the early Universe, offers a unique window into both primordial conditions and the intervening large-scale structure (LSS) it traverses. Interactions between CMB photons and…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-24 Federico Bianchini , Abhishek S. Maniyar

We study the cosmic microwave background (CMB) temperature fluctuations non-gaussianity due to the vector mode perturbations (Alfv\'en waves) supported by a stochastic cosmological magnetic field. We present detailed derivations of the…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-01 Tina Kahniashvili , George Lavrelashvili

Using the full radiation transfer function, we numerically calculate the CMB angular bispectrum seeded by the compensated magnetic scalar density mode. We find that, for the string inspired primordial magnetic fields characterized by index…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-21 Rong-Gen Cai , Bin Hu , Hong-Bo Zhang

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

Cosmic microwave background (CMB) anisotropy is our richest source of cosmological information; the standard cosmological model was largely established thanks to study of the temperature anisotropies. By the end of the decade, the Planck…

Astrophysics · Physics 2009-11-11 James G. Bartlett

We present a new probe of purely gravitationally coupled sectors with large anisotropies. These anisotropies are damped via gravitational interactions with the baryon-photon fluid, which is heated up in the process. The injected heat causes…

High Energy Physics - Phenomenology · Physics 2023-02-16 Nicklas Ramberg , Wolfram Ratzinger , Pedro Schwaller