10 papers
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…
Junction Conditions and Gravitational Collapse in Scalar-Tensor-Vector Gravity
Debanjan Debnath, Anant Badal, Kaushik Bhattacharya
We formulate the junction conditions for Scalar-Tensor-Vector Gravity (STVG/MOG), proposed by J.~W.~Moffat. Using these conditions, the theory of gravitational collapse is construc…
Redundancy of the cosmological evolution equations and its relationship with the initial conditions
Kaushik Bhattacharya, Dipanjan Dey, Priyanka Saha
It is known that in Friedmann-Lemaitre-Robertson-Walker cosmology one has more number of dynamical equations, compared to the number of unknown variables. This fact makes some equa…
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…
Dynamical systems approach to Cold and Warm Inflation within slow-roll and beyond
Sandip Biswas, Saddam Hussain, Kaushik Bhattacharya
In this work, we systematically present a new dynamical systems approach to standard inflationary processes and their variants as constant-roll inflation. Using the techniques pres…
Cosmological effect of coherent oscillation of ultralight scalar fields in a multicomponent universe
Priyanka Saha, Dipanjan Dey, Kaushik Bhattacharya
The idea that coherent oscillations of a scalar field, oscillating over a time period that is much shorter than the cosmological timescale, can exhibit cold dark matter (CDM) like…