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Inflation as the leading paradigm depicting the very early universe physics could leave imprints on the cosmic microwave background (CMB) radiation. Using currently available CMB observations, we give the tightest constraints on inflation…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-30 Deng Wang

The hemispherical power asymmetry in the cosmic microwave background may be explained by the modulation of some primordial cosmological parameter, such as the sound speed of the inflaton. This modulation can be achieved by the perturbation…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-20 Yi-Fu Cai , Wen Zhao , Yang Zhang

We study scalar mode perturbations (magnetosonic waves) induced by a helical stochastic cosmological magnetic field and derive analytically the corresponding cosmic microwave background (CMB) temperature and polarization anisotropy angular…

Astrophysics · Physics 2008-11-26 Tina Kahniashvili , Bharat Ratra

The past, present and future of cosmic microwave background (CMB) anisotropy research is discussed, with emphasis on the Boomerang and Maxima balloon experiments. These data are combined with large scale structure (LSS) information and high…

The cosmological magnetic field is one of the important physical quantities which affect strongly the cosmic microwave background (CMB) power spectrum. Recent CMB observations have been extended to higher multipoles $l\gtrsim$1000, and they…

Astrophysics · Physics 2009-11-10 D. G. Yamazaki , K. Ichiki , T. Kajino

Simple curvaton models can generate a mixture of of correlated primordial adiabatic and isocurvature perturbations. The baryon and cold dark matter isocurvature modes differ only by an observationally null mode in which the two…

Astrophysics · Physics 2009-11-07 Christopher Gordon , Antony Lewis

While the major contribution to the Cosmic Microwave Background (CMB) anisotropies are the sought-after primordial fluctuations produced at the surface of last scattering, other effects produce secondary fluctuations at lower redshifts.…

Astrophysics · Physics 2007-05-23 A. Refregier

We review the particle theory origin of inflation and curvaton mechanisms for generating large scale structures and the observed temperature anisotropy in the cosmic microwave background (CMB) radiation. Since inflaton or curvaton energy…

High Energy Physics - Phenomenology · Physics 2011-01-04 Anupam Mazumdar , Jonathan Rocher

We study effects of the cosmic string in the D-term inflation model on the cosmic microwave background (CMB) anisotropy. In the D-term inflation model, gauged cosmic string is usually formed, which may significantly affect the CMB…

High Energy Physics - Phenomenology · Physics 2009-11-10 Motoi Endo , Masahiro Kawasaki , Takeo Moroi

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…

Astrophysics · Physics 2007-05-23 Alejandro Gangui

Several accurate analyses of the CMB temperature maps from the Wilkinson Microwave Anisotropy Probe (WMAP) have revealed a set of anomalous results, at large angular scales, that appears inconsistent with the statistical isotropy expected…

Astrophysics · Physics 2009-07-22 A. Bernui , W. S. Hipolito-Ricaldi

In forthcoming years, connections between cosmology and particle physics will be made increasingly important with the advent of a new generation of cosmic microwave background (CMB) experiments. Here, we review a number of these links. Our…

Astrophysics · Physics 2008-11-26 Marc Kamionkowski , Arthur Kosowsky

Primordial magnetic fields lead to non-Gaussian signals in the Cosmic Microwave Background (CMB) even at the lowest order, as magnetic stresses, and the temperature anisotropy they induce, depend quadratically on the magnetic field. In…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-03 T. R. Seshadri , Kandaswamy Subramanian

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…

Astrophysics · Physics 2008-11-26 G. D'Amico , N. Bartolo , S. Matarrese , A. Riotto

The inflationary scenario, which states that the early universe underwent a brief but dramatic period of accelerated spatial expansion, has become the current paradigm of early universe cosmology. Although inflationary cosmology has its…

General Relativity and Quantum Cosmology · Physics 2024-06-04 Eric Ling , Annachiara Piubello

Recent observations have identified a significant 4.9$\sigma$ tension between the cosmic dipole inferred from galaxy number counts and that derived from the Cosmic Microwave Background (CMB), suggesting a potential deviation from the…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-29 Ge Chen , Chengcheng Han , Linwei Qiu

We review the present status of Cosmic Microwave Background (CMB) anisotropy observations and discuss the main related astrophysical issues, instrumental effects and data analysis techniques. We summarise the balloon-borne and ground-based…

Astrophysics · Physics 2007-05-23 M. Bersanelli , D. Maino , A. Mennella

Measurements of CMB anisotropy and, more recently, polarization have played a very important role in cosmology. Besides precise determination of various parameters of the `standard' cosmological model, observations have also established…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-02 Tarun Souradeep

We consider the stimulated emission of gravitons from an initial state of thermal equilibrium, under the action of the cosmic gravitational background field. We find that the low-energy graviton spectrum is enhanced if compared with…

General Relativity and Quantum Cosmology · Physics 2010-01-06 M. Gasperini , M. Giovannini , G. Veneziano

We examine the cosmic microwave background (CMB) anisotropy for signatures of early quintessence dark energy -- a non-negligible quintessence energy density during the recombination and structure formation eras. In contrast to a…

Astrophysics · Physics 2007-05-23 Christian M Mueller