collaborators

7 papers

astro-ph.CO2026

Accelerating expansion and isotropic sky-hemisphere consistency in Pantheon+ supernovae: a revised analysis in the dark energy debate

Saibal Ray, Maxim Khlopov, Aritra Sanyal +2

We perform four independent decompositions of the deceleration parameter using 1564 Type Ia supernovae (SNe Ia) from the Pantheon+ catalogue: by redshift bin, sky hemisphere,…

gr-qc2026

Gravastars on the brane with a timelike extra dimension

Shounak Ghosh, Rikpratik Sengupta, Kazuharu Bamba

We construct a gravastar configuration within the Shtanov-Sahni (SS) braneworld scenario, characterized by a timelike extra dimension and negative brane tension. Unlike classical b…

gr-qc2026

A Potential Black Hole Mimicker From Non-Minimal Coupling

Debanjan Debnath, Rikpratik Sengupta, Kaushik Bhattacharya

We present a class of horizonless, regular ultra-compact objects arising in a theory of gravity which allows curvature-fluid coupling. The non-minimal interaction between fluid var…

gr-qc2026

Bounce, Turnaround, and the Anisotropy Problem in Cyclic Cosmology on a Brane with a Timelike Extra Dimension

Rikpratik Sengupta, Arkajit Aich, Kaushik Bhattacharya

We study cosmological bounces, turnarounds, and cyclic evolution on an anisotropic Bianchi-I brane embedded in a five-dimensional bulk with a \emph{timelike} extra dimension, withi…

gr-qc2025

Gravitational collapse and singularity avoidance of a homogeneous dust fluid on a brane with timelike extra dimension

Rikpratik Sengupta, Chiranjeeb Singha

We investigate the gravitational collapse of a homogeneous dust cloud in the Shtanov Sahni braneworld model, which incorporates an extra timelike dimension. The interior of the col…

gr-qc2025

Co-existence of alternative Generalized Chaplygin Gas and other Dark Energies in the Framework of Fractal Universe

Mahasweta Biswas, Rikpratik Sengupta, Ujjal Debnath

We have explored the possibility of the co-existence of two forms of dark energy in the form of an alternative Generalized Chaplygin Gas (GCG) along with a scalar field of field th…