4 papers
Some remarks on the horizon in the dust cloud collapse
Koushiki, W. Piechocki, G. Plewa
We examine the existence of an apparent horizon in the collapse of an isolated dust cloud using expansion functions. Our results indicate that in the region of spacetime far away f…
Impact of Primordial Black Hole population on 21 cm observables at high redshift
Atrideb Chatterjee, Barun Maity, Koushiki
The 21-centimetre (21-cm) signal is one of the most promising probes of the high-redshift Universe. It has typically been modelled without accounting for the effects of active gala…
Apparent horizon and causal structure of spacetime singularities
Koushiki, Pankaj S. Joshi
A major issue in general relativity and blackhole physics today is to determine the conditions when the spacetime singularities forming as end-states of gravitational collapse are…
On Formation of Primordial Naked Singularities
Koushiki, Pankaj S. Joshi, Sudip Bhattacharyya
The density fluctuations in the nearly homogeneous background in the very early universe are argued to be the origin of the cosmic structures we observe in our present universe. Al…