203 citations · 3.4k across the 107 of their papers we have counts for
12 papers · 1 filter
Strong gravitational lensing --- A probe for extra dimensions and Kalb-Ramond field
Sumanta Chakraborty, Soumitra SenGupta
Strong field gravitational lensing in the context of both higher spacetime dimensions and in presence of Kalb-Ramond field have been studied. After developing proper analytical too…
Boundary terms of the Einstein-Hilbert action
Sumanta Chakraborty
The Einstein-Hilbert action for general relativity is not well posed in terms of the metric as a dynamical variable. There have been many proposals to obtain an well posed…
Constraining some Horndeski gravity theories
Sourav Bhattacharya, Sumanta Chakraborty
We discuss two spherically symmetric solutions admitted by the Horndeski (or scalar tensor) theory in the context of solar system and astrophysical scenarios. One of these solution…
Quantum leaps of black holes: Magnifying glasses of quantum gravity
Sumanta Chakraborty, Kinjalk Lochan
We show using simple arguments, that the conceptual triad of a {\it classical} black hole, semi-classical Hawking emission and geometry quantization is inherently, mutually incompa…
Buchdahl compactness limit for a pure Lovelock static fluid star
Naresh Dadhich, Sumanta Chakraborty
We obtain the Buchdahl compactness limit for a pure Lovelock static fluid star and verify that the limit following from the uniform density Schwarzschild's interior solution, which…
Entropy of a generic null surface from its associated Virasoro algebra
Sumanta Chakraborty, Sourav Bhattacharya, T. Padmanabhan
Null surfaces act as one-way membranes, blocking information from those observers who do not cross them (e.g., in the black hole and the Rindler spacetimes) and these observers ass…
1/r potential in higher dimensions
Sumanta Chakraborty, Naresh Dadhich
In Einstein gravity, gravitational potential goes as in non-compactified spacetime dimensions, which assumes the familiar form in four dimensions. On the othe…
Information retrieval from black holes
Kinjalk Lochan, Sumanta Chakraborty, T. Padmanabhan
It is generally believed that, when matter collapses to form a black hole, the complete information about the initial state of the matter cannot be retrieved by future asymptotic o…
Solving higher curvature gravity theories
Sumanta Chakraborty, Soumitra SenGupta
Solving field equations in the context of higher curvature gravity theories is a formidable task. However in many situations, e.g., in the context of theories the higher cur…
Unruh effect for inertial observers through vacuum correlations
Kinjalk Lochan, Sumanta Chakraborty, T. Padmanabhan
We study a dynamic version of the Unruh effect in a two dimensional collapse model forming a black hole. In this two-dimensional collapse model a scalar field coupled to the dilato…
Variational Principle for Gravity with Null and Non-null boundaries: A Unified Boundary Counter-term
Krishnamohan Parattu, Sumanta Chakraborty, T. Padmanabhan
It is common knowledge that the Einstein-Hilbert action does not furnish a well-posed variational principle. The usual solution to this problem is to add an extra boundary term to…
A Model of Emergent Universe in Inhomogeneous Space-Time
Subhra Bhattacharya, S. Chakraborty
A scenario of an emergent universe is constructed in the background of an inhomogeneous space-time model which is asymptotically (at spatial infinity) FRW space-time. The cosmic su…