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相关论文: Initial conditions of the universe: Decaying tenso…

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I consider the case of anisotropies in the Cosmic Microwave Background (CMB) from one single ordered perturbation source, or seed, existing well before decoupling between matter and radiation. Such structures could have been left by high…

天体物理学 · 物理学 2009-10-31 Carlo Baccigalupi

We study temperature and polarization anisotropies of the cosmic microwave background (CMB) radiation sourced from primordial cross-bispectra between metric perturbations and vector fields, which are generated from the inflation model where…

宇宙学与河外天体物理 · 物理学 2012-12-18 Maresuke Shiraishi , Shohei Saga , Shuichiro Yokoyama

In recent years, some studies have drawn attention to the lack of large-angle correlations in the observed cosmic microwave background (CMB) temperature anisotropies with respect to that predicted within the standard $\Lambda$CDM model.…

宇宙学与河外天体物理 · 物理学 2016-11-23 Gabriel R. Bengochea , Gabriel Leon

I present recent work aimed at showing how currently competing theories of the early universe leave their imprint on the temperature anisotropies of the CMB radiation. We consider the 3-point correlation function, as well as the inherent…

天体物理学 · 物理学 2007-05-23 Alejandro Gangui

The temperature and polarization anisotropies of the cosmic microwave background (CMB) have been used to set constraints on decaying dark matter models down to keV masses. In this work, we extend these limits down to the sub-keV mass range.…

宇宙学与河外天体物理 · 物理学 2024-08-27 Clara Xu , Wenzer Qin , Tracy R. Slatyer

The energy spectrum of the cosmic microwave background (CMB) allows constraining episodes of energy release in the early Universe. In this paper we revisit and refine the computations of the cosmological thermalization problem. For this…

宇宙学与河外天体物理 · 物理学 2015-05-30 J. Chluba , R. A. Sunyaev

We review the theory of the temperature anisotropy and polarization of the cosmic microwave background (CMB) radiation, and describe what we have learned from current CMB observations. In particular, we discuss how the CMB is being used to…

宇宙学与河外天体物理 · 物理学 2010-02-22 Anthony Challinor , Hiranya Peiris

We consider a novel contribution to the polarization of the Cosmic Microwave Background induced by vector and tensor modes generated by the non-linear evolution of primordial scalar perturbations. Our calculation is based on relativistic…

天体物理学 · 物理学 2009-11-10 Silvia Mollerach , Diego Harari , Sabino Matarrese

The major contribution to the anisotropy of the temperature of the Cosmic Microwave Background (CMB) radiation is believed to come from the interaction of linear density perturbations with the radiation previous to the decoupling time.…

天体物理学 · 物理学 2015-06-24 Enrique Martinez-Gonzalez

The BICEP2 collaboration reports a detection of primordial cosmic microwave background (CMB) B-mode with a tensor-scalar ratio $r=0.20^{+0.07}_{-0.05}$ (68% C.L.). However, this result is in tension with the recent Planck limit, $r<0.11$…

宇宙学与河外天体物理 · 物理学 2014-06-30 Jun-Qing Xia , Yi-Fu Cai , Hong Li , Xinmin Zhang

A principal component analysis of cosmic microwave background (CMB) anisotropy measurements is used to investigate degeneracies among cosmological parameters. The results show that a degeneracy with tensor modes -- the `tensor degeneracy'…

天体物理学 · 物理学 2009-11-07 George Efstathiou

We expose the scenarios of primordial baryon-photon plasma evolution within the framework of the Milne-like universe models. Recently, such models find a second wind and promise an inflation-free solution of a lot of cosmological puzzles…

广义相对论与量子宇宙学 · 物理学 2019-01-09 S. L. Cherkas , V. L. Kalashnikov

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

Observational Cosmology has indeed made very rapid progress in recent years. The ability to quantify the universe has largely improved due to observational constraints coming from structure formation Measurements of CMB anisotropy and, more…

天体物理学 · 物理学 2009-11-11 Tarun Souradeep

We present the initial conditions for a decaying cosmological perturbation and study its signatures in the CMB anisotropies and matter power spectra. An adiabatic decaying mode in presence of components which are not described as perfect…

天体物理学 · 物理学 2009-11-10 Luca Amendola , Fabio Finelli

In this work we investigate the effects of the primordial magnetic fields on cosmic microwave background anisotropies (CMB). Based on cosmological magnetohydrodynamic (MHD) simulations we calculate the CMB anisotropy spectra and…

天体物理学 · 物理学 2009-11-13 Hiroyuki Tashiro , Naoshi Sugiyama , Robi Banerjee

The CMB is a remarkably distortionless blackbody, and this strongly constrains the amount of energy that can have been injected at high redshift, thereby limiting the role that hydrodynamical amplification can have played in cosmic…

天体物理学 · 物理学 2009-09-25 J. Richard Bond

We investigate the impact of a stochastic background of Primordial Magnetic Fields (PMF) generated before recombination on the ionization history of the Universe and on the Cosmic Microwave Background radiation (CMB). Pre-recombination PMFs…

宇宙学与河外天体物理 · 物理学 2019-02-28 D. Paoletti , J. Chluba , F. Finelli , J. A. Rubino-Martin

Inflationary cosmology has proved to be the most successful at predicting the properties of the anisotropies observed in the cosmic microwave background (CMB). In this essay we show that quantum field renormalization significantly…

广义相对论与量子宇宙学 · 物理学 2014-11-20 Ivan Agullo , Jose Navarro-Salas , Gonzalo J. Olmo , Leonard Parker

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,…

宇宙学与河外天体物理 · 物理学 2015-06-16 Camille Bonvin , Chiara Caprini , Ruth Durrer