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We investigate the observational viability of a class of cosmological models in which the vacuum energy density decays linearly with the Hubble parameter, resulting in a production of cold dark matter particles at late times. Similarly to…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-01 C. Pigozzo , M. A. Dantas , S. Carneiro , J. S. Alcaniz

A plethora of observational data obtained over the last couple of decades has allowed cosmology to enter into a precision era and has led to the foundation of the standard cosmological constant and cold dark matter paradigm, known as the…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-31 Rubén Arjona , Savvas Nesseris

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

We report measurements of the mass density, Omega_M, and cosmological-constant energy density, Omega_Lambda, of the universe based on the analysis of 42 Type Ia supernovae discovered by the Supernova Cosmology Project. The…

The increasing tension between the different local direct measurements of the Hubble expansion rate and that inferred from the Cosmic Microwave Background observation by $\Lambda$-Cold-Dark-Matter model could be a smoking gun of new…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-30 Rong-Gen Cai , Jia-Feng Ding , Zong-Kuan Guo , Shao-Jiang Wang , Wang-Wei Yu

In this paper, linear first order expansion of deceleration parameter $q(z)=q_0+q_1(1-a)$ ($M_1$), constant jerk $j=j_0$ ($M_2$) and third order expansion of luminosity distance ($M_3$) are confronted with cosmic observations: SCP 307 SN…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-24 Lixin Xu , Wenbo Li , Jianbo Lu

Direct measurements of Hubble parameters $H(z)$ are very useful for cosmological model parameters inference. Based on them, Sahni, Shafieloo and Starobinski introduced a two-point diagnostic $Omh^2(z_i, z_j)$ as an interesting tool for…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-24 Xiaogang Zheng , Marek Biesiada , Xuheng Ding , Shuo Cao , Sixuan Zhang , Zong-Hong Zhu

A paper by Harmut Traunm\"uller [1] showed from statistical studies of observational data that the most adequate equation to represent observations on magnitude and redshift from 892 type 1a supernovae is $\mu = 5\,log[(1+z)\,ln(1+z)] +…

General Physics · Physics 2018-04-11 Jean-Marie Vigoureux , Dorian Vigoureux , Pierre Vigoureux , Michel Langlois

We use observational data from Type Ia Supernovae (SNIa), Baryon Acoustic Oscillations (BAO), and Cosmic Microwave Background (CMB), along with requirements of Big Bang Nucleosynthesis (BBN), to constrain the cosmological scenarios governed…

High Energy Physics - Theory · Physics 2015-05-14 Sourish Dutta , Emmanuel N. Saridakis

(Abridged) We investigate the power of void statistics to constrain galaxy bias and the amplitude of dark matter fluctuations. We use the halo occupation distribution (HOD) framework to describe the relation between galaxies and dark…

Astrophysics · Physics 2011-02-11 Jeremy L. Tinker , David H. Weinberg , Michael S. Warren

In this paper, we examine observational constraints on the power law cosmology; essentially dependent on two parameters $H_0$ (Hubble constant) and $q$ (deceleration parameter). We investigate the constraints on these parameters using the…

General Relativity and Quantum Cosmology · Physics 2015-03-20 Sarita Rani , A. Altaibayeva , M. Shahalam , J. K. Singh , R. Myrzakulov

We present the first Hubble diagram of superluminous supernovae (SLSNe) out to a redshift of two, together with constraints on the matter density, $\Omega_{\rm M}$, and the dark energy equation-of-state parameter, $w(\equiv p/\rho)$. We…

The $\Lambda$CDM model provides a good fit to most astronomical observations but harbors large areas of phenomenology and ignorance. With the improvements in the precision and number of observations, discrepancies between key cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-15 Jian-Ping Hu , Fa-Yin Wang

Consistency between cosmological data sets is essential for ongoing and future cosmological analyses. We first investigate the questions of stability and applicability of some moment-based inconsistency measures to multiple data sets. We…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-01 Cristhian Garcia-Quintero , Mustapha Ishak , Logan Fox , Weikang Lin

In this paper we compare data to theory. We use a compilation of the most recent cosmic microwave background (CMB) measurements to constrain Hubble's constant h, the baryon fraction Omega_b, and the cosmological constant lambda. We fit h-,…

Astrophysics · Physics 2008-02-03 Charles H. Lineweaver , Domingos Barbosa , Alain Blanchard , James G. Bartlett

We examine systematically the (in)consistency between cosmological constraints as obtained from various current data sets of the expansion history, Large Scale Structure (LSS), and Cosmic Microwave Background (CMB) from Planck. We run…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-08 Weikang Lin , Mustapha Ishak

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

The Universe may feature large-scale inhomogeneities beyond the standard paradigm, implying that statistical homogeneity and isotropy may be reached only on much larger scales than the usually assumed $\sim$100 Mpc. This means that we are…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-05 David Camarena , Valerio Marra , Ziad Sakr , Chris Clarkson

We investigate observational constraints from lensing statistics and high-z type Ia supernovae on flat cosmological models with nonrelativistic matter and an exotic fluid with equation of state, $p_x=(m/3 -1)\rho_x$. We show that agreement…

Astrophysics · Physics 2008-11-26 Ioav Waga , Ana Paula M. R. Miceli

We use updated Hubble parameter and baryon acoustic oscillation data, as well as other lower-redshift Type Ia supernova, Mg II reverberation-measured quasar, quasar angular size, H II starburst galaxy, and Amati-correlated gamma-ray burst…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-31 Shulei Cao , Bharat Ratra