68 citations · 1.1k across the 49 of their papers we have counts for
49 papers
Does Early Dark Energy Absorb the DESI Late-Time Dynamics Signal? A Combined Analysis
Mohammad Malekjani, Saeed Pourojaghi
While the recent Baryon Acoustic Oscillation (BAO) measurements from the Dark Energy Spectroscopic Instrument (DESI) collaboration are largely consistent with a flat CDM cosmolo…
How Complex is Dark Energy? A Bayesian Analysis of CPL Extensions with Recent DESI BAO Measurements
Mohammad Malekjani, Saeed Pourojaghi, Zahra Davari
The nature of dark energy is one of the big puzzling issues in cosmology. While CDM provides a good fit to the observational data, evolving dark energy scenarios, such as the CP…
CDM model against redshift-binned data: A mock analysis based on SNIa and Cosmic Chronometers
Saeed Pourojaghi, Mohammad Malekjani
Despite the broad successes of the flat CDM model and its fitness to the various cosmological observations, it confronts challenges stemming from anomalies in the measurements o…
CDM Model Against Gravity-Thermodynamics Conjecture: Observational Constraints After DESI 2024
N. Shahhoseini, M. Malekjani, A. Khodam-Mohammadi
In the context of the gravity-thermodynamics conjecture based on the Tsallis entropy-area relation, we investigate the standard CDM cosmology and examine some potential deviatio…
CDM model against cosmography: A possible deviation after DESI 2024
Saeed Pourojaghi, Mohammad Malekjani, Zahra Davari
In this study, we present an analysis of the standard flat-CDM model using a cosmographic approach, incorporating recent DESI BAO observations and Supernovae Type Ia catalogues…
Cosmological constraints on dark energy parametrizations after DESI 2024: Persistent deviation from standard CDM cosmology
M. Malekjani, Z. Davari, S. Pourojaghi
In this work, we present a study on cosmological constraints of dark energy (DE) parametrizations after the observations of Dark Energy Spectroscopic Instruments (DESI) for Baryon…
increases with effective redshift in CDM cosmology
Shahnawaz A. Adil, Özgür Akarsu, Mohammad Malekjani +4
Hubble constant and weighted amplitude of matter fluctuations determinations are biased to higher and lower values, respectively, in the late Universe with respect to e…
On Redshift Evolution & Negative Dark Energy Density in Pantheon+ Supernovae
Mohammad Malekjani, Ruairí Mc Conville, Eoin Ó Colgáin +2
Within the Friedmann-Lemaître-Robertson-Walker (FLRW) framework, the Hubble constant is an integration constant. Thus, consistency of the model demands observational constanc…
Can high-redshift Hubble diagrams rule out the standard model of cosmology in the context of cosmographic method?
S. Pourojaghi, N. F. Zabihi, M. Malekjani
Using mock data for the Hubble diagrams of type Ia supernovae (SNIa) and quasars (QSOs) generated based on the standard model of cosmology, and using the least-squares method based…
f(T) cosmology against the cosmographic method: A new study using mock and observational data
M. Sabiee, M. Malekjani, D. Mohammad Zadeh Jassur
In this paper, we study the power-law model using Hubble diagrams of type Ia supernovae (SNIa), quasars (QSOs), Gamma Ray Bursts (GRBs) and the measurements from baryonic ac…
Cosmological constrains on new generalized Chaplygin gas model
Fataneh Salahedin, Reza Pazhouhesh, Mohammad Malekjani
We use different combinations of data samples to investigate the new generalized Chaplygin gas (NGCG) model in the context of dark energy (DE) cosmology. Using the available cosmol…
New parameterizations of generalized Chaplygin gas model constrained at background and perturbation levels
S. F. Salahedin, M. Malekjani, K. Y. Roobiat +1
We study the main cosmological properties of the Generalized Chaplygin Gas (GCG) dark energy model at the background and perturbation levels. By using the latest cosmological data…
Cosmographic approach to Running Vacuum dark energy models: new constraints using BAOs and Hubble diagrams at higher redshifts
Mehdi Rezaei, Joan Sola, Mohammad Malekjani
In this work we study different types of dark energy (DE) models in the framework of the cosmographic approach, with emphasis on the Running Vacuum models (RVMs). We assess their v…
Comparison between different methods of model selection in cosmology
Mehdi Rezaei, Mohammad Malekjani
There are several methods for model selection in cosmology which have at least two major goals, that of finding the correct model or predicting well. In this work we discuss throug…
Cosmography approach to dark energy cosmologies: new constrains using the Hubble diagrams of supernovae, quasars and gamma-ray bursts
Mehdi Rezaei, Saeed Pour Ojaghi, Mohammad Malekjani
In the context of cosmography approach and using the data of Hubble diagram for supernovae, quasars and gamma-ray bursts, we study some DE parametrizations and also the concordance…
A Bayesian comparison between CDM and phenomenologically emergent dark energy models
M. Rezaei, T. Naderi, M. Malekjani +1
In this work we examine the recently proposed phenomenological emergent dark energy (PEDE) model by \cite{Li:2019yem}, using the latest observational data in both expansion and per…
Cosmological constrains on minimally and non-minimally coupled scalar field models
Zahra Davari, Valerio Marra, Mohammad Malekjani
We study the minimally and non-minimally coupled scalar field models as possible alternatives for dark energy, the mysterious energy component that is driving the accelerated expan…
Can dark energy be expressed as a power series of the Hubble parameter?
Mehdi Rezaei, Mohammad Malekjani, Joan Sola
In this work we examine the possibility that the dark energy (DE) density, can be dynamical and appear as a power series expansion of the Hubble rate (and its derivatives)…
Can Holographic dark energy models fit the observational data?
Mohammad Malekjani, Mehdi Rezaei, Iman A. Akhlaghi
In this work we investigate the holographic dark energy models with slowly time-varying model parameter defined based on the current Hubble horizon length scale. While the previous…
New parameterization for unified dark matter and dark energy
Zahra Davari, Mohammad Malekjani, Michal Artymowski
In this paper we investigate a new phenomenological parameterization for unified dark matter and dark energy based on the polynomial expansion of the barotropic equation of state p…
Model selection and constraints from Holographic dark energy scenarios
I. A. Akhlaghi, M. Malekjani, S. Basilakos +1
In this study we combine the expansion and the growth data in order to investigate the ability of the three most popular holographic dark energy models, namely event future horizon…
Constraints to dark energy using PADE parameterisations
Mehdi Rezaei, Mohammad Malekjani, Spyros Basilakos +2
We put constraints on dark energy properties using the PADE parameterisation, and compare it to the same constraints using Chevalier-Polarski-Linder (CPL) and CDM, at both the b…
Agegraphic dark energy: growth index and cosmological implications
M. Malekjani, S. Basilakos, A. Mehrabi +2
We study the main cosmological properties of the agegraphic dark energy model at the expansion and perturbation levels. Initially, using the latest cosmological data we implement a…
Spherical collapse model and cluster number counts in power law gravity
Mohammad Malekjani, Spyros Basilakos, Neda Heidari
We study the spherical collapse model (SCM) in the framework of spatially flat power law gravity model. We find that the linear and non-linear growth of sph…