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In this work we study the magnitude-redshift relation of a non-standard cosmological model. The model under consideration was firstly investigated within a special case of metric-affine gravity (MAG) and was recently recovered via different…

General Relativity and Quantum Cosmology · Physics 2009-04-03 Dirk Puetzfeld , Xuelei Chen

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

In recent years, upper limits on the cosmic microwave background (CMB) anisotropies combined with predictions made by theories of galaxy formation, have been extremely powerful in ruling out purely baryonic dark matter (BDM) universes.…

Astrophysics · Physics 2009-11-06 Louise M Griffiths , Alessandro Melchiorri , Joseph Silk

We have derived new bounds on the relativistic energy density in the Universe from cosmic microwave background (CMB), large scale structure (LSS), and type Ia supernova (SNI-a) observations. In terms of the effective number of neutrino…

Astrophysics · Physics 2009-11-13 Steen Hannestad

Massive gravity in the presence of doubly coupled matter field via en effective composite metric yields an accelerated expansion of the universe. It has been recently shown that the model admits stable de Sitter attractor solutions and…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 Lavinia Heisenberg , Alexandre Refregier

Recent re-calibration of the Type Ia supernova (SNe~Ia) magnitude-redshift relation combined with cosmic microwave background (CMB) and baryon acoustic oscillation (BAO) data have provided excellent constraints on the standard cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-02 Suhail Dhawan , Ariel Goobar , Edvard Mörtsell , Rahman Amanullah , Ulrich Feindt

We study observational constraints on the non-metricity $f(Q)$-gravity which reproduces an exact $\Lambda$CDM background expansion history while modifying the evolution of linear perturbations. To this purpose we use Cosmic Microwave…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-29 Luís Atayde , Noemi Frusciante

We use recent measurements of the dimensionless coordinate distances from Fanaroff-Riley Type IIb radio galaxies and the X-ray gas mass fractions in clusters to constrain the parameters of a non-standard cosmological model. This work…

Astrophysics · Physics 2009-04-03 Dirk Puetzfeld , Martin Pohl , Zong-Hong Zhu

Despite the ability of the cosmological concordance model ($\Lambda$CDM) to describe the cosmological observations exceedingly well, power law expansion of the Universe scale radius, $R(t)\propto t^n$, has been proposed as an alternative…

Current observational data favor cosmological models which differ from the standard model due to the presence of some form of dark energy and, perhaps, by additional contributions to the more familiar dark matter. Primordial nucleosynthesis…

Astrophysics · Physics 2009-11-07 James P. Kneller , Gary Steigman

We put constraints on the main cosmological parameters of different spatially flat cosmological models by combining the recent clustering results of XMM-Newton soft (0.5-2 keV) X-ray sources, which have a redshift distribution with median…

Astrophysics · Physics 2009-11-10 Spyros Basilakos , Manolis Plionis

We examine the constraints that can be obtained on standard cold dark matter models from the most currently used data set: CMB anisotropies, type Ia supernovae and the SDSS luminous red galaxies. We also examine how these constraints are…

Astrophysics · Physics 2015-05-13 L. D. Ferramacho , A. Blanchard , Y. Zolnierowski

We investigate the cosmological observational test of the extended quintessence model, i.e. a scalar-tensor gravity model with a scalar field potential serving as dark energy, by using the Planck 2018 cosmic microwave background (CMB) data,…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 Gong Cheng , Fengquan Wu , Xuelei Chen

We combine new Cosmic Microwave Background (CMB) data from Planck with Baryon Acoustic Oscillation (BAO) data to constrain the Brans-Dicke (BD) theory, in which the gravitational constant $G$ evolves with time. Observations of type Ia…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-19 Ji-Xia Li , Feng-Quan Wu , Yi-Chao Li , Yan Gong , Xue-Lei Chen

Observations of Type Ia supernovae (\sne), which probe the late Universe, together with baryon acoustic oscillations (BAO) and the cosmic microwave background (CMB), which probe the intermediate and early epochs, provide complementary…

Reconstructing the expansion history of the Universe from type Ia supernovae data, we fit the growth rate measurements and put model-independent constraints on some key cosmological parameters, namely, $\Omega_\mathrm{m},\gamma$, and…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-10 Benjamin L'Huillier , Arman Shafieloo , Hyungjin Kim

Non-canonical scaling of the form $\rho_{x} \propto \rho_{m} a^{\xi}$, where $\rho_{x}$ and $\rho_{m}$ are the energy densities of dark energy and dark matter, respectively, provides a natural way to address the coincidence problem -why the…

Astrophysics · Physics 2009-11-10 Diego Pavon , Somasri Sen , Winfried Zimdahl

We present robust, model-marginalized limits on both the total neutrino mass ($\sum m_\nu$) and abundance ($N_{\rm eff}$) to minimize the role of parameterizations, priors and models when extracting neutrino properties from cosmology. The…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-14 Eleonora di Valentino , Stefano Gariazzo , Olga Mena

We present new Big Bang Nucleosynthesis (BBN) limits on the cosmic expansion rate or relativistic energy density, quantified via the number $N_\nu$ of equivalent neutrino species. We use the latest light element observations, neutron mean…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-01 Tsung-Han Yeh , Jessie Shelton , Keith A. Olive , Brian D. Fields

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…

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