Bharat Ratra

activity

20242026

collaborators

10 papers

astro-ph.CO2026

Updated observational constraints on $I ¨ $ CDM dynamical dark energy cosmological models

Chan-Gyung Park, Bharat Ratra

We present updated observational constraints on the spatially flat $I ¨ $ CDM model, where dark energy is described by a minimally coupled scalar field $I ¨ $ with an inverse power-law…

astro-ph.CO2026

Is the $w_{0} w_{a}$ CDM cosmological parameterization evidence for dark energy dynamics partially caused by the excess smoothing of Planck PR4 CMB anisotropy data?

Javier de Cruz PÃ©rez, Chan-Gyung Park, Bharat Ratra

We study the performance of the flat $I^$ CDM model and the dynamical dark energy parameterizations $w_{0}$ CDM and $w_{0} w_{a}$ CDM, in which the dark energy (DE) equation of state is eith…

astro-ph.GA2025

Standardizing reverberation-mapped H $I^^{2}$ active galactic nuclei using time-averaged radius $-$ luminosity relations with 5100\,Ã \,, broad H $I^^{2}$ , and narrow \OIII\ luminosities

Shulei Cao, Amit Kumar Mandal, Michal ZajaÄek +1

Active galactic nuclei (AGN) have been studied as alternate probes in cosmology due to their large and stable luminosities and broad redshift range. Previously it was shown that hi…

astro-ph.CO2025

Is the $w_{0} w_{a}$ CDM cosmological parameterization evidence for dark energy dynamics partially caused by the excess smoothing of Planck CMB anisotropy data?

Chan-Gyung Park, Javier de Cruz Perez, Bharat Ratra

We study the performance of the spatially-flat dynamical dark energy (DE) $w_{0} w_{a}$ CDM parameterization, with redshift-dependent DE fluid equation of state parameter $w(z) = w_0 + w…

astro-ph.CO2025

Testing the consistency of new Amati-correlated gamma-ray burst dataset cosmological constraints with those from better-established cosmological data

Shulei Cao, Bharat Ratra

Gamma-ray bursts (GRBs) are promising cosmological probes for exploring the Universe at intermediate redshifts ( $z$ ). We analyze 151 Fermi-observed long GRBs (datasets A123 and A28…

astro-ph.GA2025

Standardizing a larger, higher-quality, homogeneous sample of reverberation-mapped H $I^^{2}$ active galactic nuclei using the broad-line region radius-luminosity relation

Shulei Cao, Amit Kumar Mandal, Michal ZajaÄek +1

We present a high-quality, homogeneous sample of 157 H $I^^{2}$ reverberation-mapped active galactic nuclei (RM AGNs) spanning redshifts $0.00308 \leq z \leq 0.8429$ , which is approxima…

Updated observational constraints on I¨CDM dynamical dark energy cosmological models

Is the w0​wa​CDM cosmological parameterization evidence for dark energy dynamics partially caused by the excess smoothing of Planck PR4 CMB anisotropy data?

Standardizing reverberation-mapped HI^2 active galactic nuclei using time-averaged radius−luminosity relations with 5100\,Ã \,, broad HI^2, and narrow \OIII\ luminosities

Is the w0​wa​CDM cosmological parameterization evidence for dark energy dynamics partially caused by the excess smoothing of Planck CMB anisotropy data?