Related papers: $\Lambda$CDM model against redshift-binned data: A…
We carry out a comparative analysis of the standard $\Lambda$CDM cosmological model and the alternative $R_h=ct$ framework using recent observational data from cosmic chronometers (CC), Type Ia supernova, and baryon acoustic oscillations.…
We use simulated Hubble parameter data in the redshift range 0 \leq z \leq 2 to explore the role and power of observational H(z) data in constraining cosmological parameters of the {\Lambda}CDM model. The error model of the simulated data…
Cosmographic approach, a Taylor expansion of the Hubble function, has been used as a model-independent method to investigate the evolution of the universe in the presence of cosmological data. Apart from possible technical problems like the…
Motivated by recent claims of a possible redshift dependence in late-Universe determinations of the Hubble constant (H_0), we test the robustness of this behavior using multiple cosmological probes. We perform a joint redshift-binned…
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…
We search for possible deviations from the expectations of the concordance $\Lambda$CDM model in the expansion history of the Universe by analysing the Pantheon Type Ia Supernovae (SnIa) compilation along with its Monte Carlo simulations…
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…
In this paper we summarise the constraints that low-redshift data --such as supernovae Ia (SN Ia), baryon acoustic oscillations (BAO) and cosmic chronometers (CC)-- are able to set on the concordance model and its extensions, as well as on…
The magnitude-redshift relation is one of the tools for a direct observational approach to cosmology. The discovery of high redshift Type Ia supernovae (SNIa) and their use as ``standard candles'' has resurrected interest in this approach.…
Standard cosmology is constructed upon the (generally implicit) assumption of the ``large scale'' homogeneity of our Universe. Now, structures are observed at scales which become larger and larger as the observational distances increase.…
It has recently been pointed out by Kowalski et. al. (arxiv:0804.4142) that there is `an unexpected brightness of the SnIa data at z>1'. We quantify this statement by constructing a new statistic which is applicable directly on the Type Ia…
The Brans-Dicke model with a variable cosmological term ($BD\Lambda$) has been investigated with use of the coupling constant of $\omega=10^4$. Parameters inherent in this model are constrained from comparison between Big Bang…
We use the Simon, Verde, & Jimenez (2005) determination of the redshift dependence of the Hubble parameter to constrain cosmological parameters in three dark energy cosmological models. We consider the standard $\Lambda$CDM model, the XCDM…
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…
Given the persistence of various tensions in the "Cosmic Concordance" -- such as the "Hubble Tension", and possible departures from LambdaCDM time evolution -- seen from combinations of complementary data sets (e.g., Cosmic Microwave…
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…
In view of the current and increasing evidence of a running Hubble constant, we investigate its redshift dependence within the flat $\Lambda$CDM framework using a 20-bin analysis of the Master SNe~Ia Sample \citep{2025JHEAp..4800405D},…
The case of SN Ia Hubble diagrams from photometrically selected samples using photometric SN host galaxy redshifts is investigated. The host redshift uncertainties and the contamination by core collapse SNe are addressed. As a test, we use…
Analyses by the Dark Energy Spectroscopic Instrument (DESI) collaboration suggest a significant deviation from the $\Lambda$CDM model when their baryon acoustic oscillation (BAO) measurements are combined with Planck cosmic microwave…
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…