activity
20242026
collaborators

9 papers

astro-ph.CO2026

Beyond : Observational Constraints on Almost-CDM Cosmologies

Jess Worsley, Saikat Chakraborty, Peter Dunsby

The cosmographic condition provides the kinematical signature of the spatially flat CDM model independently of any specific dark-energy or modified-gravity theory. We…

gr-qc2026

Reconstructing the slope of a nearly flat quintessence potential from cosmography

Saikat Chakraborty, Peter K. S. Dunsby, Robert J. Scherrer

We revisit thawing quintessence models with nearly flat scalar-field potentials using a cosmographic framework. Earlier work indicates that the cosmographic reconstruction of the s…

astro-ph.CO2026

Constraining Scale-Dependent Growth in Gravity with Future 21 cm Surveys

Apurba Samanta, Bhuwan Joshi, Jess Worsley +2

Recent observations, particularly from DESI, have provided intriguing hints of dynamical behaviour in late-time dark energy. Modified gravity theories offer a compelling framework…

gr-qc2026

Direct cosmographic reconstruction of the quintessence potential

Saikat Chakraborty, Peter K. S. Dunsby, Robert J. Scherrer

We derive expressions for the first and second derivatives of the quintessence potential , in terms of and , as…

gr-qc2025

A Unified Dynamical Systems Framework for Cosmology in Gravity: Generic Features Beyond the Coincident Gauge

Jibitesh Dutta, Wompherdeiki Khyllep, Saikat Chakraborty +2

We present a unified dynamical systems framework for spatially flat FLRW cosmology in gravity, covering all three connection branches via a single set of Hubble-normalised v…

gr-qc2025

Dynamical dark energy in models with evolution close to CDM

Saikat Chakraborty, Charlotte Louw, Peter K. S. Dunsby +2

In this communication we address whether or not there is an equivalence between the kinematical and dynamical descriptions of the spatially flat CDM model. We address this by i…