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We propose a fast and efficient bispectrum statistic for Cosmic Microwave Background (CMB) temperature anisotropies to constrain the amplitude of the primordial non-Gaussian signal measured in terms of the non-linear coupling parameter…

天体物理学 · 物理学 2009-11-11 P. Cabella , F. K. Hansen , M. Liguori , D. Marinucci , S. Matarrese , L. Moscardini , N. Vittorio

We present the computation of the full system of Boltzmann equations at second-order describing the evolution of the photon, baryon and cold dark matter fluids. These equations allow to follow the time evolution of the Cosmic Microwave…

天体物理学 · 物理学 2011-09-16 N. Bartolo , S. Matarrese , A. Riotto

We present a fully covariant and gauge-invariant calculation of the evolution of anisotropies in the cosmic microwave background (CMB) radiation. We use the physically appealing covariant approach to cosmological perturbations, which…

天体物理学 · 物理学 2008-11-26 Anthony Challinor , Anthony Lasenby

Measurements of CMB anisotropy are ideal experiments for discovering the non-trivial global topology of the universe. To evaluate the CMB anisotropy in multiply-connected compact cosmological models, one needs to compute eigenmodes of the…

天体物理学 · 物理学 2007-05-23 Kaiki Taro Inoue

CMB anisotropy measurements have brought the issue of global topology of the universe from the realm of theoretical possibility to within the grasp of observations. The global topology of the universe modifies the correlation properties of…

天体物理学 · 物理学 2009-10-31 J. Richard Bond , Dmitry Pogosyan , Tarun Souradeep

Upcoming cosmic microwave background (CMB) data can be used to explore harmonic 3-point functions that involve the B-mode component of the CMB polarization signal. We focus on bispectra describing the non-Gaussian correlation of the B-mode…

宇宙学与河外天体物理 · 物理学 2020-07-15 Adriaan J. Duivenvoorden , P. Daniel Meerburg , Katherine Freese

The angular power spectrum of the Cosmic Microwave Background (CMB) anisotropies is a key tool to study the Universe. However, it is blind to the presence of non--Gaussianities and deviations from statistical isotropy, which instead can be…

宇宙学与河外天体物理 · 物理学 2024-01-26 Alessandro Carones , Javier Carrón Duque , Domenico Marinucci , Marina Migliaccio , Nicola Vittorio

We present two simple analytical methods for computing the gravity wave contribution to the cosmic background radiation (CBR) anisotropy in inflationary models; one method uses a time-dependent transfer function, the other method uses an…

天体物理学 · 物理学 2009-10-28 Yun Wang

We develop the formalism necessary to study four-point functions of the cosmic microwave background (CMB) temperature and polarization fields. We determine the general form of CMB trispectra, with the constraints imposed by the assumption…

天体物理学 · 物理学 2011-05-12 Takemi Okamoto , Wayne Hu

Accurate measurements of the cosmic microwave background (CMB) anisotropies with an angular resolution of a few arcminutes can be used to determine fundamental cosmological parameters such as the densities of baryons, cold and hot dark…

天体物理学 · 物理学 2016-01-13 J. Richard Bond , George Efstathiou , Max Tegmark

Cosmic microwave background (CMB) observations provide in principle a high-precision test of models which are motivated by M theory. We set out the framework of a program to compute the tensor anisotropies in the CMB that are generated in…

天体物理学 · 物理学 2009-11-07 Bernard Leong , Anthony Challinor , Roy Maartens , Anthony Lasenby

Cosmic microwave background (CMB) anisotropies and density fluctuations are calculated for flat cold dark matter (CDM) models with a wide range of parameters, i.e., $\Omega_0, h$ and $\Omega_B$ for both standard recombination and various…

天体物理学 · 物理学 2009-10-22 Naoshi Sugiyama

We put into test the idea of replacing dark energy by a vector field against the cosmic microwave background (CMB) observation using the simplest vector-tensor theory, where a massive vector field couples to the Ricci scalar and the Ricci…

广义相对论与量子宇宙学 · 物理学 2026-01-21 Rui Xu , Dandan Xu , Lars Andersson , Pau Amaro Seoane , Lijing Shao

Inflation gives rise to a nearly scale-invariant spectrum of tensor perturbations (gravitational waves), their contribution to the Cosmic Background Radiation (CBR) anisotropy depends upon the present cosmological parameters as well as…

天体物理学 · 物理学 2014-10-13 Michael S. Turner , Yun Wang

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

Accurate measurements of the Cosmic Microwave Background (CMB) anisotropy call for high precision and reliability of the in-flight calibration. For extended surveys the CMB dipole provides an excellent calibration source at frequencies…

天体物理学 · 物理学 2009-11-10 B. Cappellini , D. Maino , G. Albetti , P. Platania , R. Paladini , A. Mennella , M. Bersanelli

We describe an algorithm to generate temperature and polarization maps of the cosmic microwave background radiation containing non-Gaussianity of arbitrary local type. We apply an optimized quadrature scheme that allows us to predict and…

宇宙学与河外天体物理 · 物理学 2024-06-04 Franz Elsner , Benjamin D. Wandelt

The measurements of CMB anisotropy have opened up a window for probing the global topology of the universe on length scales comparable to and beyond the Hubble radius. For compact topologies, the two main effects on the CMB are: (1) the…

天体物理学 · 物理学 2011-04-15 J. Richard Bond , Dmitri Pogosyan , Tarun Souradeep

The Cosmic Linear Anisotropy Solving System (CLASS) is a new accurate Boltzmann code, designed to offer a more user-friendly and flexible coding environment to cosmologists. CLASS is very structured, easy to modify, and offers a rigorous…

天体物理仪器与方法 · 物理学 2011-05-17 Julien Lesgourgues

We obtain the non-linear generalization of the Sachs-Wolfe + integrated Sachs-Wolfe (ISW) formula describing the CMB temperature anisotropies. Our formula is valid at all orders in perturbation theory, is also valid in all gauges and…

宇宙学与河外天体物理 · 物理学 2017-09-06 Omar Roldan