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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…

高能物理 - 唯象学 · 物理学 2023-02-16 Nicklas Ramberg , Wolfram Ratzinger , Pedro Schwaller

The arrival directions of TeV-PeV cosmic rays are remarkably uniform due to the isotropization of their directions by scattering on turbulent magnetic fields. Small anisotropies can exist in standard diffusion models, however, only on the…

高能天体物理现象 · 物理学 2022-03-14 Marco Kuhlen , Vo Hong Minh Phan , Philipp Mertsch

We use the cosmic microwave background temperature anisotropy to place limits on large-scale magnetic fields in an inhomogeneous (perturbed Friedmann) universe. If no assumptions are made about the spacetime geometry, only a weak limit can…

天体物理学 · 物理学 2017-08-23 C. A. Clarkson , A. A. Coley , R. Maartens , C. G. Tsagas

The Cosmic Microwave Background (CMB) anisotropy power on the largest angular scales observed both by WMAP and COBE DMR appears to be lower than the one predicted by the standard model of cosmology with almost scale free primordial…

天体物理学 · 物理学 2009-09-29 Carlo R. Contaldi , Marco Peloso , Lev Kofman , Andrei Linde

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…

宇宙学与河外天体物理 · 物理学 2025-01-24 Federico Bianchini , Abhishek S. Maniyar

A conventional explanation of the dipole anisotropy of the cosmic microwave background (CMB) radiation is in terms of the Doppler effect: our galaxy is moving with respect to CMB frame with $ \sim 600 ~ km ~ s^{-1} $. However, as the deep…

天体物理学 · 物理学 2007-05-23 M. Jaroszynski , B. Paczynski

In the standard picture of cosmic ray transport the propagation of charged cosmic rays through turbulent magnetic fields is described as a random walk with cosmic rays scattering on magnetic field turbulence. This is in good agreement with…

高能天体物理现象 · 物理学 2021-07-08 Marco Kuhlen , Philipp Mertsch , Vo Hong Minh Phan

We explore the large angular scale temperature anisotropies in the cosmic microwave background due to expanding homogeneous local voids at redshift z~1. A compensated spherically symmetric homogeneous dust-filled void with radius \~3*10^2…

天体物理学 · 物理学 2008-11-26 Kaiki Taro Inoue , Joseph Silk

We report measurements of anisotropy in the cosmic microwave background radiation over the multipole range l ~ 200 - 3500 with the Cosmic Background Imager based on deep observations of three fields. These results confirm the drop in power…

Primordial magnetic fields generated in the very early universe are one of the candidates for the origin of magnetic fields observed in galaxy clusters. After recombination, the Lorentz force acts on the residual ions and electrons to…

宇宙学与河外天体物理 · 物理学 2021-04-28 Hiroyuki Tashiro , Naoshi Sugiyama

We use the TNG50 cosmological magnetohydrodynamical simulation of the IllustrisTNG project to show that magnetic fields in the circumgalactic medium (CGM) have significant angular structure. This azimuthal anisotropy at fixed distance is…

星系天体物理 · 物理学 2023-10-11 Rahul Ramesh , Dylan Nelson , Volker Heesen , Marcus Brüggen

We review the recently found large-scale anomalies in the maps of temperature anisotropies in the cosmic microwave background. These include alignments of the largest modes of CMB anisotropy with each other and with geometry and direction…

宇宙学与河外天体物理 · 物理学 2012-12-10 Craig J. Copi , Dragan Huterer , Dominik J. Schwarz , Glenn D. Starkman

Motivated by stability considerations and observational evidence, we argue that magnetars possess highly-tangled internal magnetic fields. We propose that the quasi-periodic oscillations (QPOs) seen to accompany giant flares can be…

高能天体物理现象 · 物理学 2016-05-25 Bennett Link , C. Anthony van Eysden

The distribution of arrival directions of cosmic rays is remarkably isotropic, which is a consequence of their repeated scattering in magnetic fields. Yet, high-statistics observatories like IceCube and HAWC have revealed the presence of…

高能天体物理现象 · 物理学 2019-12-04 Philipp Mertsch , Markus Ahlers

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…

天体物理学 · 物理学 2009-11-11 James G. Bartlett

In the first part of this work, I review the theoretical framework of cosmological perturbation theory necessary to understand the generation and evolution of cosmic microwave background (CMB) anisotropies. Using analytical and numerical…

天体物理学 · 物理学 2009-09-29 Roberto Trotta

Damping of magnetic fields via ambipolar diffusion and decay of magnetohydrodynamical (MHD) turbulence in the post decoupling era heats the intergalactic medium (IGM). Delayed recombination of hydrogen atoms in the IGM yields an optical…

宇宙学与河外天体物理 · 物理学 2015-05-26 Kerstin E. Kunze , Eiichiro Komatsu

The cosmic microwave background anisotropy is sensitive to the slope and amplitude of primordial energy density and gravitational wave fluctuations, the baryon density, the Hubble constant, the cosmological constant, the ionization history,…

天体物理学 · 物理学 2008-11-26 J. R. Bond , Robert Crittenden , Richard L. Davis , George Efstathiou , Paul J. Steinhardt

In this paper we present a complete computation of the Cosmic Microwave Background (CMB) anisotropies up to third order from gravitational perturbations accounting for scalar, vector and tensor perturbations. We then specify our results to…

天体物理学 · 物理学 2008-11-26 G. D'Amico , N. Bartolo , S. Matarrese , A. Riotto

Cosmic microwave background (CMB) anisotropies probe the primordial density field at the edge of the observable Universe. There is a limiting precision (``cosmic variance'') with which anisotropies can determine the amplitude of primordial…

天体物理学 · 物理学 2016-08-25 Marc Kamionkowski , Abraham Loeb