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Related papers: Omega from the COBE-DMR anisotropy maps

200 papers

A 2.29 GHz VLBI all-sky survey of ultra-compact radio sources has formed the basis of a number of cosmological investigations, which examine the relationship between angular-size and redshift. Here I use a sample of 468 such sources with…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-12 J. C. Jackson

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

Small departures from a homogeneous isotropic spacetime create observable features in the large-scale anisotropy of the cosmic microwave background. We cross-correlate the maps of the cosmic microwave background anisotropy from the Cosmic…

Astrophysics · Physics 2009-10-30 A. Kogut , G. Hinshaw , A. J. Banday

We derive the implications for anisotropies in the cosmic microwave background following from a model of inflation in which a bare cosmological constant is gradually screened by an infrared process in quantum gravity. The model predicts…

Astrophysics · Physics 2015-06-24 L. R. Abramo , N. C. Tsamis , R. P. Woodard

Recent analyses of the WMAP data have suggested that the low-order multipoles of the CMB anisotropy distribution show cosmologically interesting and unexpected morphologies and amplitudes. In this paper, we apply a power equalization (PE)…

Astrophysics · Physics 2009-11-10 P. Bielewicz , K. M. Gorski , A. J. Banday

The cosmic curvature $\Omega_{K}$ is an important parameter related to the inflationary cosmology and the ultimate fate of the universe. In this work, we adopt the non-CMB observations to constrain $\Omega_{K}$ in the $\Lambda$CDM model and…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-12 Peng-Ju Wu , Xin Zhang

Flat cosmological models with a cosmological constant on the order of the Einstein-de Sitter critical density are enigmatic in the sense that there does not appear to be any natural explanation for why there should be a cosmological…

Astrophysics · Physics 2007-05-23 George Chapline

We perform a joint likelihood analysis of the power spectra of the 2dF Galaxy Redshift Survey (2dFGRS) and the cosmic microwave background (CMB) anisotropies under the assumptions that the initial fluctuations were adiabatic, Gaussian and…

An analysis of the Cosmological Constant $\Omega_\Lambda$ fitted to subsamples of the Pantheon+ Type Ia SN sample spanning 2$\pi$ sterradians for a grid of 432 pole positions covering the whole sky reveals two large scale asymmetries. One…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-04 Alejandro Clocchiatti , Ósmar Rodríguez , Ariel Órdenes Morales , Benjamín Cuevas-Tapia

We investigate the existence and meaning of a preferred length in the large-scale distribution of 60-micron IRAS sources applying three tests to the 2-dimensional distribution on the celestial sphere, involving respectively the rms…

Astrophysics · Physics 2011-05-23 R. Fabbri , V. Natale

Cut-sky orthogonal mode analyses of the COBE-DMR 53 and 90 GHz sky maps are used to determine the normalization of a variety of open cosmogonical models based on the cold dark matter scenario. To constrain the allowed cosmological-parameter…

Astrophysics · Physics 2008-11-26 K. M. Gorski , B. Ratra , R. Stompor , N. Sugiyama , A. J. Banday

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. We have developed a new method for calculating the CMB anisotropy in…

Astrophysics · Physics 2007-05-23 Tarun Souradeep , Dmitry Pogosyan , J. Richard Bond

The geometry of Freedman-Roberston-Walker cosmological models is fixed by the mass density parameter, Omega_M, and the cosmological constant, Omega_Lambda. The classical volume-redshift cosmological relation is a sensitive…

Astrophysics · Physics 2007-05-23 R. G. Carlberg

We compute the cosmic microwave background (CMB) anisotropy in a low-density, flat, cosmological constant, cold dark matter model which is normalized to the two-year COBE DMR sky map. Although conclusions regarding model viability must…

Astrophysics · Physics 2015-06-24 Bharat Ratra , Naoshi Sugiyama

Astronomical measurements of the Omegas for mass density, cosmological constant lambda and curvature k are shown to be sufficient to produce a unique and detailed cosmological model describing dark energy influences based on the Friedman…

General Physics · Physics 2010-01-14 James G. Gilson

Observations of large scale structure (LSS) and the Cosmic Microwave Background (CMB) each place separate constraints on the values of cosmological parameters. We calculate a joint likelihood based on various CMB experiments and the IRAS…

Astrophysics · Physics 2007-05-23 Matthew Webster , S. L. Bridle , M. P. Hobson , A. N. Lasenby , Ofer Lahav , Graca Rocha

We present properties of the peaks (maxima) of the CMB anisotropies expected in flat and open CDM models. We obtain analytical expressions of several topological descriptors: mean number of maxima and the probability distribution of the…

Astrophysics · Physics 2009-10-28 R. B. Barreiro , J. L. Sanz , E. Martinez-Gonzalez , L. Cayon , Joseph Silk

We compare and combine likelihood functions of the cosmological parameters Omega_m, h and sigma_8, from peculiar velocities, CMB and type Ia supernovae. These three data sets directly probe the mass in the Universe, without the need to…

Astrophysics · Physics 2009-10-31 S. L. Bridle , I. Zehavi , A. Dekel , O. Lahav , M. P. Hobson , A. N. Lasenby

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

Observational constraints guide one forcefully to examine models in which the matter density is substantially less than critical density. Particularly noteworthy are those which are consistent with inflation. For these models, microwave…

Astrophysics · Physics 2007-05-23 J. P. Ostriker , Paul J. Steinhardt
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