48 citations · 114 across the 15 of their papers we have counts for
15 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…
Redshift Dependence of Dipole in Pantheon+ Supernovae
M. H. Jalali-Kanafi, E. Ó Colgáin, S. Pourojaghi +1
We examine the dipole structure in the local cosmic expansion rate using the Pantheon+ compilation of Type Ia supernovae. We reconstruct directional maps of across the…
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…
Crosschecking Cosmic Distances from DESI BAO and DES SNe
Mauricio Lopez-Hernandez, Eoin Ó Colgáin, Saeed Pourojaghi +1
We perform a consistency check of DESI DR2 BAO constraints ( by reconstructing the same quantities from DES supernovae (SNe) in bins with the same effective reds…
On the Analysis Dependence of DESI Dynamical Dark Energy
Eoin Ó Colgáin, Saeed Pourojaghi, M. M. Sheikh-Jabbari
We continue scientific scrutiny of the DESI dynamical dark energy (DE) claim by explicitly demonstrating that the result depends on the analysis pipeline. Concretely, we define a l…
How much has DESI dark energy evolved since DR1?
Eoin Ó Colgáin, Saeed Pourojaghi, M. M. Sheikh-Jabbari +1
DESI has reported a dynamical dark energy (DE) signal based on the CDM model that is in conflict with Hubble tension. Recalling that the combination of DESI DR1 BAO and DR…
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 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…
Implications of DES 5YR SNe Dataset for CDM
Eoin Ó Colgáin, Saeed Pourojaghi, M. M. Sheikh-Jabbari
Dark Energy Survey five-year supernovae data (DES 5YR SNe) in conjunction with Planck CMB and Dark Energy Spectroscopic Instrument (DESI) BAO data has detected a strong dynamical d…
Does DESI 2024 Confirm CDM?
Eoin Ó Colgáin, Maria Giovanna Dainotti, Salvatore Capozziello +3
We demonstrate that a discrepancy with the Planck-CDM cosmology in DESI Luminous Red Galaxy (LRG) data in the redshift range with effective redshift $…
A comparison of Bayesian and frequentist confidence intervals in the presence of a late Universe degeneracy
Eoin Ó Colgáin, Saeed Pourojaghi, M. M. Sheikh-Jabbari +1
Hubble tension is a problem in one-dimensional (1D) posteriors, since local determinations are only sensitive to a single parameter. Projected 1D posteriors for CDM cosmol…
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…