, , and other constraints from lower-redshift, non-CMB, expansion-rate data

S Cao, B Ratra - Physical Review D, 2023 - APS
We use updated type Ia Pantheon+ supernova, baryon acoustic oscillation, and Hubble
parameter (now also accounting for correlations) data, as well as new reverberation …

Do gamma-ray burst measurements provide a useful test of cosmological models?

N Khadka, O Luongo, M Muccino… - Journal of Cosmology …, 2021 - iopscience.iop.org
We study eight different gamma-ray burst (GRB) data sets to examine whether current GRB
measurements—that probe a largely unexplored part of cosmological redshift (z) space …

Constraints on cosmological parameters from gamma-ray burst peak photon energy and bolometric fluence measurements and other data

N Khadka, B Ratra - Monthly Notices of the Royal Astronomical …, 2020 - academic.oup.com
We use measurements of the peak photon energy and bolometric fluence of 119 gamma-ray
bursts (GRBs) extending over the redshift range of 0.3399≤ z≤ 8.2 to simultaneously …

Effect of extinction on quasar luminosity distances determined from UV and X-ray flux measurements

M Zajaček, B Czerny, N Khadka… - The Astrophysical …, 2024 - iopscience.iop.org
In Khadka et al., a sample of X-ray-detected reverberation-mapped quasars was presented
and applied for the comparison of cosmological constraints inferred using two well …

Gaussian processes reconstruction of the dark energy potential

JF Jesus, R Valentim, AA Escobal… - … of Cosmology and …, 2022 - iopscience.iop.org
Scalar Fields (SF) have emerged as natural candidates for dark energy as quintessential or
phantom fields, as they are the main ingredient of inflation theories. Instead of assuming …

Reconstruction of latetime cosmology using principal component analysis

R Sharma, A Mukherjee, HK Jassal - The European Physical …, 2022 - epjplus.epj.org
We reconstruct late-time cosmology using the technique of Principal Component Analysis
(PCA). In particular, we focus on the reconstruction of the dark energy equation of state from …

Perturbations in tachyon dark energy and their effect on matter clustering

A Singh, HK Jassal, M Sharma - Journal of Cosmology and …, 2020 - iopscience.iop.org
A non-canonical scalar tachyon field is a viable candidate for dark energy and has been
found to be in good agreement with observational data. Background data alone cannot …

Interacting tachyonic scalar field II

VK Ojha, AA Rao, SD Pathak - arXiv preprint arXiv:2305.00277, 2023 - arxiv.org
The existence of dark energy is essential to explain the cosmic accelerated expansion. We
consider a homogenous interacting tachyonic scalar field as a possible candidate for the …

Inference of cosmological models with principal component analysis

R Sharma, HK Jassal - Journal of Astrophysics and Astronomy, 2024 - Springer
Determination of cosmological parameters is a major goal in cosmology at present. The
availability of improved data sets necessitates the development of novel statistical tools to …

Evolution of matter perturbations and observational constraints on tachyon scalar field model

F Felegary, IA Akhlaghi, H Haghi - Physics of the Dark Universe, 2020 - Elsevier
In this paper, the tachyon scalar field model is compared with the Λ CDM standard model
using a set of observational data consisting of BBN, H (z), CMB, BAO, SNIa and f (z) σ 8. The …