5 papers
Spherically Symmetric, Static Solutions in Presence of Matter-Curvature Coupling
Debanjan Debnath, Kaushik Bhattacharya
In this work we have proposed some spherically symmetric, static spacetimes in a theory of gravity which permits non-minimal coupling (NMC) between curvature of spacetime and fluid…
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…
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…
Non-minimal coupling of scalar fields in the dark sector and generalization of the top-hat collapse
Priyanka Saha, Dipanjan Dey, Kaushik Bhattacharya
In this article, we propose a new way to handle interactions between two scalar fields in the cosmological backdrop where one scalar field oscillates rapidly in the cosmological ti…
End equilibrium state of a spherical gravitational collapse in the presence of matter and scalar field
Debanjan Debnath, Dipanjan Dey, Kaushik Bhattacharya
We explore the possibilities of modeling a spherically symmetric static spacetime that can emerge as the end state of gravitational collapse, by considering it to be seeded by a co…