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We investigate a statistical anisotropy on the Cosmic Microwave Background (CMB) bispectrum, which can be generated from the primordial non-Gaussianity induced by quantum fluctuations of a vector field. We find new configurations in the…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-03 Maresuke Shiraishi , Shuichiro Yokoyama

Persisting tensions between the cosmological constraints derived from low-redshift probes and the ones obtained from temperature and polarisation anisotropies of the Cosmic Microwave Background -- although not yet providing compelling…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-14 Marco Baldi , Fergus Simpson

The power spectrum of fluctuations in the cosmic microwave background (CMB) depends on most of the key cosmological parameters. Accurate future measurements of this power spectrum might therefore allow us to determine h, Omega, Omega_b,…

Astrophysics · Physics 2007-05-23 Max Tegmark

The effect of gravitational lensing on cosmic microwave background (CMB) anisotropies is investigated using the power spectrum approach. The lensing effect can be calculated in any cosmological model by specifying the evolution of…

Astrophysics · Physics 2009-10-28 Uros Seljak

We develop a formalism for calculating cosmic microwave background (CMB) temperature and polarization anisotropies in cosmological models with Brans-Dicke gravity. We then modify publicly available Boltzmann codes to calculate numerically…

Astrophysics · Physics 2008-11-26 Xuelei Chen , Marc Kamionkowski

We discuss the non-Gaussian contribution to the power spectrum covariance of cosmic microwave background (CMB) anisotropies resulting through weak gravitational lensing angular deflections and the correlation of deflections with secondary…

Astrophysics · Physics 2009-11-07 Asantha Cooray

Much of modern cosmology relies on the Cosmological Principle, the assumption that the Universe is isotropic and homogeneous on sufficiently large scales, but it remains worthwhile to examine cosmological models that violate this principle…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-01 Ananda F. Smith , Craig J. Copi , Glenn D. Starkman

We study observational constraints on the non-metricity $f(Q)$-gravity which reproduces an exact $\Lambda$CDM background expansion history while modifying the evolution of linear perturbations. To this purpose we use Cosmic Microwave…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-29 Luís Atayde , Noemi Frusciante

In this paper we provide a prescription for obtaining a small non-Gaussianity and the observed dipole asymmetry in the cosmic microwave background radiation. The observations inevitably lead to multi-field inflationary dynamics, where each…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-22 Lingfei Wang , Anupam Mazumdar

I review the general aspects of cosmological parameter estimation from observations of the cosmic microwave background (CMB) temperature anisotropies in the framework of inflationary adiabatic models. The most recent CMB datasets are…

Astrophysics · Physics 2009-10-31 A. Balbi

The leading candidate for the very early universe is described by a period of rapid expansion known as inflation. While the standard paradigm invokes a single slow-rolling field, many different models may be constructed which fit the…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-30 D. M. Regan

Angular power spectra of temperature anisotropies and polarization of the cosmic microwave background (CMB) as well as the linear matter power spectra are calculated for models with three light neutrinos with non-thermal phase-space…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-24 Kerstin E. Kunze

We work in the framework of an inflationary cold dark matter universe with cosmological constant, in which the cosmological inhomogeneities are considered as gravitational lenses for the CMB photons. This lensing deforms the angular…

Astrophysics · Physics 2009-11-10 P. Cerdá-Durán , V. Quilis , D. Sáez

The weak lensing effect on the cosmic microwave background (CMB) induces distortions in spatial pattern of CMB anisotropies, and statistical properties of CMB anisotropies become a weakly non-Gaussian field. We first summarize the weak…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-17 Toshiya Namikawa

Observers have demonstrated that it is now feasible to measure the cosmic microwave background (CMB) temperature at high redshifts. We explore the possible constraints on cosmology which might ultimately be derived from such measurements.…

Astrophysics · Physics 2009-11-07 John M. LoSecco , Grant J. Mathews , Yun Wang

Weak gravitational lensing changes the angular power spectra of the cosmic microwave background (CMB) temperature and polarization in a characteristic way containing valuable information for cosmological parameter estimation and weak…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Philipp Merkel , Bjoern Malte Schaefer

A future detection of the Stochastic Gravitational Wave Background (SGWB) with GW experiments is expected to open a new window on early universe cosmology and on the astrophysics of compact objects. In this paper we study SGWB anisotropies,…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-22 N. Bartolo , D. Bertacca , S. Matarrese , M. Peloso , A. Ricciardone , A. Riotto , G. Tasinato

We show that the difference between the theoretically expected and measured by WMAP amplitude of the quadrupole fluctuations of CMB can be related to the impact of the anisotropic curvature of the homogeneous universe dominated by the dark…

Astrophysics · Physics 2008-11-26 M. Demiański , A. G. Doroshkevich

Spatially fluctuating primordial magnetic fields (PMFs) inhomogeneously reheat the Universe when they dissipate deep inside the horizon before recombination. Such an energy injection turns into an additional photon temperature perturbation.…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-28 Shohei Saga , Atsuhisa Ota , Hiroyuki Tashiro , Shuichiro Yokoyama

Weak lensing distortion of the background cosmic microwave background (CMB) temperature and polarization patterns by the foreground density fluctuations is well studied in the literature. We discuss the gravitational lensing modification to…

Astrophysics · Physics 2009-11-11 Chao Li , Asantha Cooray
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