49 citations · 91 across the 17 of their papers we have counts for
19 papers
Gravitational physics in the context of Indian astronomy: A vision document
P. Ajith, K. G. Arun, Sukanta Bose +13
Contributions from the Indian gravity community have played a significant role in shaping several branches of astronomy and astrophysics. This document reviews some of the most imp…
Torsion and Chern-Simons gravity in 4D space-times from a Geometrodynamical four-form
Patrick Das Gupta
The space-time geometry in any inertial frame is described by the line-element . Now, not only the Minkowski metric is invariant under proper Loren…
Observed Trends in FRB Population and Bi-modality in their Peak Luminosity Density Distribution
Nidhi Saini, Patrick Das Gupta
Fast radio bursts (FRBs) are radio transients of extragalactic origin lasting for about a few to several milli-seconds. We have analyzed both non-CHIME and CHIME FRB data. To circu…
Black Hole Menagerie, Charged/Dyonic BHs and Radiation from Interacting Dyonic BH Pairs
Patrick Das Gupta, Mohd. Sirtaz
We describe charged BHs, Penrose process for energy extraction from Kerr BHs and Wald's proposal concerning a Kerr BH slowly becoming a Kerr-Newman BH in the presence of a uniform…
Aspects of Black Hole Physics and Formation of Super-massive Black Holes from Ultra-light Dark Bosons
Patrick Das Gupta, Fazlu Rahman
First, we verify that the physical parameters estimated for the four directly detected gravitational wave (GW) events involving coalescence of binary black holes (BHs) indeed uphol…
Collapsing supra-massive magnetars: FRBs, the repeating FRB121102 and GRBs
Patrick Das Gupta, Nidhi Saini
Fast radio bursts (FRBs) last for few milli-seconds and, hence, are likely to arise from the gravitational collapse of supra-massive, spinning neutron stars after they lose…
Comets, historical records and vedic literature
Patrick Das Gupta
A verse in book I of Rigveda mentions a cosmic tree with rope-like aerial roots held up in the sky. Such an imagery might have ensued from the appearance of a comet having `tree st…
General Relativity for Pedestrians -- First 6 lectures
Patrick Das Gupta
The 2017 Nobel Prize in physics awarded to Rainer Weiss, Barry C. Barish and Kip S. Thorne has generated unprecedented interest in gravitational waves (GWs). These notes are based…
Supermassive Black Holes from self-gravitating Bose-Einstein Condensates comprised of Ultra-light Bosonic Dark Matter
Patrick Das Gupta, Eklavya Thareja
Observed active galactic nuclei at redshifts suggest that supermassive black holes (SMBHs) had formed early on. Accretion of matter onto remnants of Population III star…
Mathemagical 2014 - An Indian Perspective
Patrick Das Gupta
Mathematics is probably the only subject that can be classified both as art as well as science - former, because it is not constrained by the real world and latter because it is a…
General Relativity and Compact Objects
Patrick Das Gupta
Starting with the conceptual foundation of general relativity (GR) - equivalence principle, space-time geometry and special relativity, I train cross hairs on two characteristic pr…
Gravity, Bose-Einstein Condensates and Gross-Pitaevskii Equation
Patrick Das Gupta
We explore the effect of mutual gravitational interaction between ultra-cold gas atoms on the dynamics of Bose-Einstein condensates (BEC). Small amplitude oscillation of BEC is stu…
Comets in ancient India
Patrick Das Gupta
The Indo-aryans of ancient India observed stars and constellations for ascertaining auspicious times in order to conduct sacrificial rites ordained by vedas. It is but natural that…
Gravitational waves in the presence of a dynamical four-form
Patrick Das Gupta
Propagation of weak gravitational waves, when a dynamical four-form is around, has been investigated. Exact, self-consistent solutions corresponding to plane, monochromatic gravita…
S. Chandrasekhar: White Dwarfs, ion,.., Black holes, Gravitational waves
Patrick Das Gupta
This is a concise review, addressed to undergraduate students, of S. Chandrasekhar's oeuvre in astrophysics, ranging from his early studies on white dwarfs using relativistic quant…
Mystery of the Cosmological Constant
Patrick Das Gupta
The 2011 Nobel prize in physics has been awarded to S. Perlmutter, A. Riess and B. Schmidt for their path breaking discovery that the rate of expansion of the universe is increasin…
On Chern-Simons corrections to magnetohydrodynamics equations
Patrick Das Gupta
We study the effect of a (3+1)-dimensional Chern-Simons electrodynamics on the equations governing the dynamics of magnetized plasma and fields. In this model, the Chern-Simons (CS…
Dark energy and Chern-Simons like gravity from a dynamical four-form
Patrick Das Gupta
We consider the dynamics of a four-form field , treating it as a distinct physical degree of freedom, independent of the metric. The equations of motion are derived fr…
Baryogenesis from Primordial Blackholes after Electroweak Phase Transition
Niraj Upadhyay, Patrick Das Gupta, R. P. Saxena
Incorporating a realistic model for accretion of ultra-relativistic particles by primordial blackholes (PBHs), we study the evolution of an Einstein-de Sitter universe consisting o…