39 citations · 51 across the 10 of their papers we have counts for
9 papers · 1 filter
Stability Analysis of Axion Dark Energy Model
Ankan Mukherjee, Nandan Roy
We investigate the stability of an axion dark energy model characterized by a periodic scalar-field potential motivated by pseudo Nambu Goldstone bosons. While such models are well…
Kruglov-entropy cosmology from apparent-horizon thermodynamics: background dynamics and observational constraints
Candrasyah Muhammad, Burin Gumjudpai, Nandan Roy +1
We investigate two late-time cosmological models generated by Kruglov's nonadditive entropy at the apparent horizon. Model I, originally derived by Kruglov, follows the Cai--Kim th…
Observational constraints on scalar-vector-tensor dark energy with phantom-divide crossing
Nandan Roy, Shinji Tsujikawa, Ying-li Zhang +1
We constrain a scalar-vector-tensor (SVT) dark-energy model in which the vector sector drives the dark-energy equation of state below at earlier times, while a canonical scala…
The role of anisotropy in gravity: insights from cosmological observations
Ghulam Murtaza, Nandan Roy, Avik De
We investigate the cosmological dynamics of Bianchi-I spacetime in symmetric teleparallel gravity through a dynamical system approach to analyse observational constraints. B…
-CDM: A Minimal Deformation of CDM with Scalar Field Reconstruction
Phichayoot Baisri, Nandan Roy, Prasanta Sahoo +2
Recent DESI BAO observations provide intriguing hints that dark energy may be dynamical in nature. To investigate deviations of the dark energy equation of state (EoS) from $w = -1…
CosmoDS: A Python toolkit for constraining cosmological models via dynamical systems analysis with Cobaya
Nandan Roy, Prasanta Sahoo
We present a toolkit, CosmoDS, designed to study cosmological models at the background level using dynamical system analysis within the Cobaya framework. Dynamical system analysis…
Dynamical Systems in Cosmology: Reviewing An Alternative Approach
Nandan Roy, L. Arturo Ureña-López
Dark energy is one of the deepest puzzles in modern cosmology, and mounting evidence suggests that it is not just a cosmological constant but a genuinely dynamical component. Altho…
Chiellini-Integrable Cosmologies with Phantom Divide Crossing
Soumya Chakrabarti, Nandan Roy
We investigate exact cosmological solutions with a massive scalar field minimally coupled to the Einstein-Hilbert action in General Relativity. For an extended Higgs-like scalar se…
Quintom Dark Energy: Future Attractor and Phantom Crossing in Light of DESI DR2 Observation
Phusuda Thanankullaphong, Prasanta Sahoo, Prajwal Hassan Puttasiddappa +1
We study the late-time cosmological dynamics of a two-field dark energy model consisting of a canonical quintessence scalar field and a phantom scalar field in a spatially flat FLR…