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We reexamine constraints on the spatial size of closed toroidal models with cold dark matter and the cosmological constant from cosmic microwave background. We carry out Bayesian analyses using the Cosmic Background Explorer (COBE) data…

Astrophysics · Physics 2009-11-07 Kaiki Taro Inoue , Naoshi Sugiyama

We reconstruct the non-linear matter power spectrum $P(k)$ using a joint analysis of gravitational lensing of the cosmic microwave background (CMB) and lensing of galaxies. This reconstruction is motivated by the $S_8$ tension between…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-11 Karen Perez Sarmiento , Alex Laguë , Mathew Madhavacheril , Bhuvnesh Jain , Blake Sherwin

We use large-scale cosmological observations to place constraints on the dark-matter pressure, sound speed and viscosity, and infer a limit on the mass of warm-dark-matter particles. Measurements of the cosmic microwave background (CMB)…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-08 Martin Kunz , Savvas Nesseris , Ignacy Sawicki

The current standard model of cosmology, the LambdaCDM model, is based on the homogeneous FLRW solutions of the Einstein equations to which some perturbations are added to account for the CMB features and structure formation at large…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-14 Marie-Noëlle Célérier

The apparent accelerating expansion of the Universe is forcing us to examine the foundational aspects of the standard model of cosmology -- in particular, the fact that dark energy is a direct consequence of the homogeneity assumption. We…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-21 Chris Clarkson , Roy Maartens

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

We compare a large suite of theoretical cosmological models to observational data from the cosmic microwave background, baryon acoustic oscillation measurements of expansion, Type Ia SNe measurements of expansion, redshift space distortion…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-13 Zhongxu Zhai , Michael Blanton , Anže Slosar , Jeremy Tinker

It has been recently proposed that the presence of a temporal electromagnetic field on cosmological scales could explain the phase of accelerated expansion that the universe is currently undergoing. The field contributes as a cosmological…

General Physics · Physics 2009-11-13 Jose Beltran Jimenez , Tomi S. Koivisto , Antonio L. Maroto , David F. Mota

It has been argued that the power spectrum of the anisotropies in the Cosmic Microwave Background (CMB) may be effectively degenerate, namely that the observable spectrum does not determine a unique set of cosmological parameters. We…

Astrophysics · Physics 2015-06-24 R. Benton Metcalf , Joseph Silk

The standard model of cosmology, {\Lambda}CDM, is the simplest model that matches the current observations, but it relies on two hypothetical components, to wit, dark matter and dark energy. Future galaxy surveys and cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-13 Cyrille Doux , Mariana Penna-Lima , Sandro D. P. Vitenti , Julien Tréguer , Eric Aubourg , Ken Ganga

The residuals of the power spectra of WMAP and Planck's cosmic microwave background (CMB) anisotropies data are known to exhibit a few interesting anomalies at different scales with marginal statistical significance. Combining bottom-up and…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-01 Matteo Braglia , Xingang Chen , Dhiraj Kumar Hazra

We present an extensive comparison of models of structure formation with observations, based on linear and quasi-linear theory. We assume a critical matter density, and study both cold dark matter models and cold plus hot dark matter…

Astrophysics · Physics 2015-06-24 Andrew R Liddle , David H Lyth , R K Schaefer , Q Shafi , Pedro T P Viana

We study the Cosmic Microwave Background (CMB) anisotropies produced by cosine-type quintessence models. In our analysis, effects of the adiabatic and isocurvature fluctuations are both taken into account. For purely adiabatic fluctuations…

Astrophysics · Physics 2007-05-23 Tomo Takahashi

The dimming of Type Ia supernovae could be the result of Hubble-scale inhomogeneity in the matter and spatial curvature, rather than signaling the presence of a dark energy component. A key challenge for such models is to fit the detailed…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-22 Chris Clarkson , Marco Regis

In the covariant cosmological perturbation theory, a 1+3 decomposition ensures that all variables in the frame-independent equations are covariant, gauge-invariant and have clear physical interpretations. We develop this formalism in the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-18 Fengquan Wu , Li-e Qiang , Xin Wang , Xuelei Chen

We investigate the consequences of an imperfect dark energy component on the large scale structure. A phenomenological three parameter fluid description is used to study the effect of dark energy on the cosmic microwave background radiation…

Astrophysics · Physics 2009-11-13 Tomi Koivisto , David F. Mota

We use some of the recently released observational data to test the viability of two classes of minimally coupled scalar field models of quintessence with exponential potentials for which exact solutions of the Einstein equations are known.…

Astrophysics · Physics 2009-11-10 M. Demianski , E. Piedipalumbo , C. Rubano , C. Tortora

Assuming that the cosmological principle holds, Maartens, Ellis and Stoeger (MES) recently constructed a detailed scheme linking anisotropies in the cosmic background radiation (CMB) with anisotropies and inhomogeneities in the large scale…

Astrophysics · Physics 2008-12-01 William Stoeger , Marcelo Araujo , Tim Gebbie

We investigate the accuracy attainable by forthcoming space-based observations of the cosmic microwave background (CMB) temperature and polarization anisotropy in constraining the dark energy density parameter $\Oq$ and equation of state…

Astrophysics · Physics 2009-11-07 A. Balbi , C. Baccigalupi , F. Perrotta , S. Matarrese , N. Vittorio

We study the cosmic microwave background (CMB) in the framework of the degenerate higher-order scalar-tensor (DHOST) theory to test gravity theories. This theoretical framework includes the wide class of dark energy models such as the…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-28 Takashi Hiramatsu , Daisuke Yamauchi
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