activity
20242026
collaborators

6 papers

astro-ph.CO2026

Cosmological perturbations with gravity scalarons : Galaxy power spectra and the scalaron mass

Abhijit Talukdar, Sanjeev Kalita, Shadab Alam

In this paper we study cosmological perturbations with gravity scalaron. We consider epoch of transition from early general relativity (GR) phase to late time non-GR phase o…

astro-ph.CO2026

Cosmology-Independent Constraints on the Etherington Relation and SNeIa Absolute Magnitude Evolution from DESI-DR2

Sourav Das, Surhud More, Shadab Alam

We carry out a test of the fundamental Etherington relation (cosmic distance duality relation) which relates the luminosity distance and angular diameter distance $D_{\…

astro-ph.CO2026

Stabilizing simulation-based cosmological Fisher forecasts: a case study using the Voronoi volume function

Saee Dhawalikar, Aseem Paranjape, Shadab Alam

Forecasting cosmological constraints from halo-based statistics often suffers from instability in derivative estimates, especially when the number of simulations is limited. This i…

astro-ph.CO2025

Detection of cosmological dipoles aligned with transverse peculiar velocities

Yan-Chuan Cai, John A. Peacock, Anna de Graaff +1

Peculiar velocities encode rich cosmological information, but their transverse components are hard to measure. Here, we present the first observations of a novel effect of transver…

astro-ph.CO2024

The Early Data Release of the Dark Energy Spectroscopic Instrument

DESI Collaboration, A. G. Adame, J. Aguilar +266

The Dark Energy Spectroscopic Instrument (DESI) completed its five-month Survey Validation in May 2021. Spectra of stellar and extragalactic targets from Survey Validation constitu…

astro-ph.CO2024

The Atacama Cosmology Telescope DR6 and DESI: Structure growth measurements from the cross-correlation of DESI Legacy Imaging galaxies and CMB lensing from ACT DR6 and Planck PR4

Frank J. Qu, Qianjun Hang, Gerrit Farren +51

We measure the growth of cosmic density fluctuations on large scales and across the redshift range through the cross-correlation of the ACT DR6 CMB lensing map and gala…