English
Related papers

Related papers: Testing cosmological models and understanding cosm…

200 papers

The background photon temperature $\bar T$ is one of the fundamental cosmological parameters. Despite its significance, $\bar T$ has never been allowed to vary in the data analysis, owing to the precise measurement of the comic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-18 Jaiyul Yoo , Ermis Mitsou , Yves Dirian , Ruth Durrer

We present simulations of a cosmic shear survey and show how the survey geometry influences the accuracy of determination of cosmological parameters. We numerically calculate the full covariance matrices of the two-point statistics \xi_+,…

Astrophysics · Physics 2007-05-23 Martin Kilbinger

We use current cosmic microwave background data to constrain cosmological parameters. The results are presented as confidence regions in the ($\Omega$--$H_o$) -- plane for both open and flat geometries, and are based on a $\chi^2$…

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

We perform a new and accurate study of the dependence on cosmological parameters of structure formation with local cosmic strings. The crucial new ingredients are the inclusion of the effects of gravitational backreaction on the evolution…

Astrophysics · Physics 2009-10-31 E. J. Copeland , Joao Magueijo , D. A. Steer

Interpretation of cosmological data to determine the number and values of parameters describing the universe must not rely solely on statistics but involve physical insight. When statistical techniques such as "model selection" or…

Astrophysics · Physics 2011-08-31 Eric V. Linder , Ramon Miquel

I present a series of diagrams which illustrate why the cosmic microwave background (CMB) data favor certain values for the cosmological parameters. Various methods to extract these parameters from CMB and non-CMB observations are forming…

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

Recent cosmic microwave background (CMB) results from BOOMERANG, MAXIMA, and DASI provide cosmological constraints on new physics that can be competitive with those derived from Big Bang Nucleosynthesis (BBN). In particular, both CMB and…

Astrophysics · Physics 2008-11-26 James P. Kneller , Robert J. Scherrer , Gary Steigman , Terry P. Walker

The cosmological consequences of an interacting model in which vacuum decay law is deducted from the effect that vacuum decay has on the dark matter evolution are investigated. Here, the baryonic matter is also considered as a fluid…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-27 H. T. C. M. Souza , N. Pires , F. E. M. Costa , F. C. Carvalho , E. P. Bento

The Cosmic Microwave Background (CMB) is an abundant source of cosmological information. However, this information is encoded in non-trivial ways in a signal that is difficult to observe. The resulting challenges in extracting this…

Astrophysics · Physics 2014-10-13 Benjamin D. Wandelt

We present an extended analytic model for cosmic star formation, with the aim of investigating the impact of cosmological parameters on the star formation history within the $\Lambda$CDM paradigm. Constructing an ensemble of flat…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-13 Daniele Sorini , John A. Peacock , Lucas Lombriser

The cosmic microwave background temperature is a cornerstone astrophysical observable. Its present value is tightly constrained, but its redshift dependence, which can now be determined until redshift $z\sim6.34$, is also an important probe…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-23 L. Gelo , C. J. A. P. Martins , N. Quevedo , A. M. M. Vieira

Determinations of the main cosmological parameters are reviewed and the implications for cold dark matter discussed. There is no longer an age problem for an $\Omega_o = 1, \Lambda = 0$ model and, if anything, there is now an age problem…

Astrophysics · Physics 2007-05-23 M. Rowan-Robinson

Numerical simulations of galaxy formation require a number of parameters. Some of these are intrinsic to the numerical integration scheme (eg the timestep), while others describe the physical model (eg the gas metallicity). In this paper,…

Because the baryon-to-photon ratio eta_{10} is in some doubt, we drop nucleosynthetic constraints on eta_{10} and fit the three cosmological parameters (h, Omega_M, eta_{10}) to four observational constraints: Hubble parameter h_o =…

Astrophysics · Physics 2009-10-30 G. Steigman , N. Hata , J. E. Felten

Knowledge of the constants that describe the current cosmological world model, H_0, t_0, and the three Omega's is central to physical cosmology. Although there is a vast range of suggested tests and existing constraints much of the recent…

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

We show that upcoming CMB satellite experiments and large redshift surveys can be used together to yield 5% determinations of H_0 and Omega_m, an order of magnitude improvement over CMB data alone. CMB anisotropies provide the sound horizon…

Astrophysics · Physics 2015-06-24 Daniel J. Eisenstein , Wayne Hu , Max Tegmark

We use higher-redshift gamma-ray burst (GRB), HII starburst galaxy (HIIG), and quasar angular size (QSO-AS) measurements to constrain six spatially flat and non-flat cosmological models. These three sets of cosmological constraints are…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-15 Shulei Cao , Joseph Ryan , Narayan Khadka , Bharat Ratra

Recent works have discovered a relatively tight correlation between $\Omega_{\rm m}$ and properties of individual simulated galaxies. Because of this, it has been shown that constraints on $\Omega_{\rm m}$ can be placed using the properties…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-22 Chaitanya Chawak , Francisco Villaescusa-Navarro , Nicolas Echeverri Rojas , Yueying Ni , ChangHoon Hahn , Daniel Angles-Alcazar

We use cosmography to present constraints on the kinematics of the Universe, without postulating any underlying theoretical model. To this end, we use a Monte Carlo Markov Chain analysis to perform comparisons to the supernova Ia Union 2…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Alejandro Aviles , Christine Gruber , Orlando Luongo , Hernando Quevedo

Data from Type Ia supernovae, along with X-ray cluster estimates of the universal baryon fraction and Big Bang Nucleosynthesis (BBN) determinations of the baryon-to-photon ratio, are used to provide estimates of several global cosmological…

Astrophysics · Physics 2007-05-23 G. Steigman , T. P. Walker , A. Zentner