activity
20142025
most citedTheoretical and observational constraints on the HI intensity power spectrum

60 citations · 148 across the 8 of their papers we have counts for

collaborators

8 papers

astro-ph.CO2025

Conditioning halos on the tidal environment for fast and accurate HI power spectra during reionization

Gaurav Pundir, Tirthankar Roy Choudhury, Aseem Paranjape

Predicting the statistical properties of the neutral hydrogen (HI) density field during reionization is an important step in using upcoming 21 cm observations to constrain models o…

astro-ph.CO2024★ 2 cited

Accelerating HI density predictions during the Epoch of Reionization using a GPR-based emulator on N-body simulations

Gaurav Pundir, Aseem Paranjape, Tirthankar Roy Choudhury

Building fast and accurate ways to model the distribution of neutral hydrogen during the Epoch of Reionization (EoR) is essential for interpreting upcoming 21 cm observations. A ke…

astro-ph.CO2023★ 1 cited

Covariance matrices for the Lyman- forest using the lognormal approximation

Bhaskar Arya, Aseem Paranjape, Tirthankar Roy Choudhury

We investigate the nature of correlations in the small-scale flux statistics of the Lyman- (Ly) forest across redshift bins. Understanding these correlations is important for…

astro-ph.CO2023

A modified lognormal approximation of the Lyman- forest: comparison with full hydrodynamic simulations at

Bhaskar Arya, Tirthankar Roy Choudhury, Aseem Paranjape +1

Observations of the Lyman- forest in distant quasar spectra with upcoming surveys are expected to provide significantly larger and higher-quality datasets. To interpret these da…

astro-ph.CO2015★ 25 cited

Photon Number Conserving Models of H II Bubbles during Reionization

Aseem Paranjape, T. Roy Choudhury, Hamsa Padmanabhan

Traditional excursion set based models of H II bubble growth during the epoch of reionization are known to violate photon number conservation, in the sense that the mass fraction i…

astro-ph.CO2015★ 31 cited

Modelling the cosmic neutral hydrogen from DLAs and 21 cm observations

Hamsa Padmanabhan, T. Roy Choudhury, Alexandre Refregier

We review the analytical prescriptions in the literature to model the 21-cm (emission line surveys/intensity mapping experiments) and Damped Lyman-Alpha (DLA) observations of neutr…

astro-ph.CO2014★ 60 cited

Theoretical and observational constraints on the HI intensity power spectrum

Hamsa Padmanabhan, T. Roy Choudhury, Alexandre Refregier

Mapping of the neutral hydrogen (HI) 21-cm intensity fluctuations across redshifts promises a novel and powerful probe of cosmology. The neutral hydrogen gas mass density, $Ω_{\rm…

astro-ph.CO2014★ 29 cited

An improved model of HII bubbles during the epoch of reionization

Aseem Paranjape, T. Roy Choudhury

The size distribution of ionized regions during the epoch of reionization -- a key ingredient in understanding the HI power spectrum observable by 21cm experiments -- can be modell…