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Related papers: CMBology

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We perform a detailed analysis of the latest CMB measurements (including BOOMERaNG, DASI, Maxima and CBI), both alone and jointly with other cosmological data sets involving, e.g., galaxy clustering and the Lyman Alpha Forest. We first…

Astrophysics · Physics 2009-09-25 Xiaomin Wang , Max Tegmark , Matias Zaldarriaga

We show that the cosmic microwave background (CMB) data of WMAP can give subelectronvolt limit on the neutrino mass: m_nu < 0.63 eV (95% CL). We also investigate its degeneracy with other cosmological parameters. In particular, we show the…

Astrophysics · Physics 2008-11-26 Kazuhide Ichikawa

We investigate some properties of flat cosmological models with a $\Lambda$ term that decreases with time as $\Lambda \propto a^{-m}$ (a is the scale factor and m is a parameter $0\leq m < 3$). The models are equivalent to standard…

Astrophysics · Physics 2009-10-30 V. Silveira , I. Waga

The power spectrum of mass density fluctuations is evaluated from the Mark III and the SFI catalogs of peculiar velocities by a maximum likelihood analysis, using parametric models for the power spectrum and for the errors. The applications…

Astrophysics · Physics 2007-05-23 Idit Zehavi , Avishai Dekel

The current enthusiam to measure fluctuations in the CMB power spectrum at angular scales between 0.1 and 1 degree is largely motivated by the expectation that CMB determinations of cosmological parameters will be of unprecedented…

Astrophysics · Physics 2007-05-23 C. H. Lineweaver

Recent measurements of the parameters of the Concordance Cosmology Model ($\Lambda$CDM) done in the low-redshift Universe with Supernovae Ia/Cepheids, and in the distant Universe done with Cosmic Microwave Background (CMB) imply different…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 B. Czerny , M. L. Martínez-Aldama , G. Wojtkowska , M. Zajaček , P. Marziani , D. Dultzin , M. H. Naddaf , S. Panda , R. Prince , R. Przyluski , M. Ralowski , M. Śniegowska

We discuss the constraints one can place on cosmological parameters using current cosmic microwave background data. A standard $\chi^2$--minimization over band--power estimates is first presented, followed by a discussion of the more…

Astrophysics · Physics 2007-05-23 J. G. Bartlett , A. Blanchard , M. Douspis , M. Le Dour

In this paper we investigate the statistical properties of gravitational lenses for models in which a cosmological term decreases with time as $\Lambda \propto a^{-m}$, where $a$ is the scale factor and $m$ is a parameter ($0 \leq m < 3$).…

Astrophysics · Physics 2015-06-24 L. F. Bloomfield Torres , I. Waga

The simplest cosmological model ($\Lambda$CDM) is well-known to suffer from the Hubble tension, namely an almost $5 \sigma$ discrepancy between the (model-based) early-time determination of the Hubble constant $H_0$ and its late-time (and…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-06 Darshan Kumar , Debajyoti Choudhury , Debottam Nandi

Cosmological constraints are usually derived under the assumption of a $6$ parameters $\Lambda$-CDM theoretical framework or simple one-parameter extensions. In this paper we present, for the first time, cosmological constraints in a…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-30 Eleonora Di Valentino , Alessandro Melchiorri , Joseph Silk

We present limits on the cosmological constant from the statistics of gravitational lenses using newly completed quasar surveys, new lens data, and a range of lens models. The formal limit is $\lambda_0 < 0.66$ at 95\% confidence in flat…

Astrophysics · Physics 2009-10-28 C. S. Kochanek

We investigate a simple braneworld model in which the universe contains only cold dark matter and a cosmological constant, but the effective dark energy is phantom-like because of extra-dimensional gravity effects. Modified gravity screens…

Astrophysics · Physics 2014-10-13 Ruth Lazkoz , Roy Maartens , Elisabetta Majerotto

Dark energy can be studied by its influence on the expansion of the Universe as well as on the growth history of the large-scale structure. In this paper, we follow the growth of the cosmic density field in early dark energy cosmologies by…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-22 Lukas Hollenstein , Domenico Sapone , Robert Crittenden , Bjoern Malte Schaefer

We perform a combined likelihood analysis of the latest cosmic microwave background anisotropy data and distant Type 1a Supernova data of Perlmutter etal (1998a). Our analysis is restricted to cosmological models where structure forms from…

Astrophysics · Physics 2009-10-31 G. Efstathiou , S. L. Bridle A. N. Lasenby , M. P. Hobson , R. S. Ellis

After a short history of the $\Lambda$-term it is explained why the (effective) cosmological constant is expected to obtain contributions from short-distance physics, corresponding to an energy at least as large as the Fermi scale. The…

Astrophysics · Physics 2007-05-23 Norbert Straumann

We compare various physically different measurements of linear matter density perturbation amplitude, $sigma_8$, which are obtained from the observations of CMB anisotropy, galaxy cluster mass function, weak gravitation lensing, matter…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-03 R. A. Burenin

We are now beginning to learn detailed information about cosmological parameters from the shapes of the matter and radiation power spectra, together with their relative normalization. As more high quality data are gathered from galaxy…

Astrophysics · Physics 2007-05-23 Douglas Scott
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