203 citations · 3.4k across the 107 of their papers we have counts for
108 papers
Equivalence of the wave function of the universe in the Einstein and Jordan frames
Vikramaditya Mondal, Sumanta Chakraborty, Soumitra SenGupta
We investigate the question of equivalence between the Einstein and Jordan frames for generic scalar-tensor and gravity theories in the context of minisuperspace quantum cos…
Galactic wormholes: Geometry, stability, and echoes
Shauvik Biswas, Chiranjeeb Singha, Sumanta Chakraborty
In this work, we present the environmental effects on wormholes residing in a galaxy. By this, we propose that these wormholes are mimickers of supermassive black holes residing at…
Addressing issues in defining the Love numbers for black holes
Rajendra Prasad Bhatt, Sumanta Chakraborty, Sukanta Bose
We present an analytic method for calculating the tidal response function of a nonrotating and a slowly rotating black hole from the Teukolsky equation in the small-frequency and n…
Lorentzian quantum cosmology with torsion
Vikramaditya Mondal, Sumanta Chakraborty
We evaluate the Lorentzian gravitational path integral in the presence of non-vanishing torsion with the application of the Picard-Lefschetz theory for minisuperspaces correspondin…
Perturbing the perturbed: Stability of quasinormal modes in presence of a positive cosmological constant
Subhodeep Sarkar, Mostafizur Rahman, Sumanta Chakraborty
In this work, we wish to address the question -- whether the quasi-normal modes, the characteristic frequencies associated with perturbed black hole spacetimes, central to the stab…
Distinguishing cosmological models through quantum signatures of primordial perturbations
Rathul Nath Raveendran, Sumanta Chakraborty
We study the evolution of various measures of quantumness of the curvature perturbation by integrating out the inaccessible entropic fluctuations in the multi-field models of infla…
Transition from inspiral to plunge for braneworld EMRI
Sajal Mukherjee, Sumanta Chakraborty
In the present article, we discuss the late inspiral and then the transition regime to the plunge phase of a secondary, less massive compact object into a more massive braneworld b…
Shielding a charged black hole
Justin C. Feng, Sumanta Chakraborty, Vitor Cardoso
We describe a shielding mechanism for a charged black hole immersed in a background involving charged matter fields, solely arising from the Einstein-Maxwell field equations. In pa…
Dynamical Love for area quantized black holes
Sreejith Nair, Sumanta Chakraborty, Sudipta Sarkar
We study the tidal deformability of horizonless exotic compact objects, with implications for area quantized black holes. Since, any such horizonless compact object, including area…
Hunting extra dimensions in the shadow of Sgr A*
Indrani Banerjee, Sumanta Chakraborty, Soumitra SenGupta
We show that the observed angular diameter of the shadow of the ultra compact object Sgr A*, favours the existence of an extra spatial dimension. This holds irrespective of the nat…
Gravitational wave memory in wormhole spacetimes
Indranil Chakraborty, Soumya Bhattacharya, Sumanta Chakraborty
Gravitational wave memory is studied in the context of a certain class of braneworld wormholes. Unlike other wormhole geometries, this novel class of wormholes do not require any e…
Echoes from braneworld wormholes
Shauvik Biswas, Mostafizur Rahman, Sumanta Chakraborty
We have studied the stability of wormhole geometries, under massless scalar, electromagnetic and axial gravitational perturbations, in the context of higher dimensional spacetimes.…
Universality of the Buchdahl sphere
Sumanta Chakraborty, Naresh Dadhich
Buchdahl sphere, the limiting stable isotropic stellar structure without exotic matter, plays a very important role in our understanding of how compact an astrophysical object can…
Strong cosmic censorship conjecture for a charged BTZ black hole
Chiranjeeb Singha, Sumanta Chakraborty, Naresh Dadhich
The strong cosmic censorship conjecture, whose validation asserts the deterministic nature of general relativity, has been studied for charged BTZ black holes in three dimensional…
Implications of the quantum nature of the black hole horizon on the gravitational-wave ringdown
Sumanta Chakraborty, Elisa Maggio, Anupam Mazumdar +1
Motivated by capturing putative quantum effects at the horizon scale, we model the black hole horizon as a membrane with fluctuations following a Gaussian profile. By extending the…
Scalar perturbations around rotating regular black holes and wormholes: quasi-normal modes, ergoregion instability and superradiance
Edgardo Franzin, Stefano Liberati, Jacopo Mazza +2
We study scalar test-field perturbations on top of a Kerr--black-bounce background, i.e. a family of rotating regular black holes and/or rotating traversable wormholes that can mim…
Microscopic origin of Einstein's field equations and the raison d'être for a positive cosmological constant
T. Padmanabhan, Sumanta Chakraborty
In the paradigm of effective field theory, one hierarchically obtains the effective action for some low(er) energy degrees of freedom , by int…
Bound on photon circular orbits in general relativity and beyond
Sumanta Chakraborty
Existence of a photon circular orbit can tell us a lot about the nature of the underlying spacetime, since it plays a pivotal role in the understanding of the characteristic signat…
Supertranslations at Timelike Infinity
Sumanta Chakraborty, Debodirna Ghosh, Sk Jahanur Hoque +2
We propose a definition of asymptotic flatness at timelike infinity in four spacetime dimensions. We present a detailed study of the asymptotic equations of motion and the action o…
Weiss variation for general boundaries
Justin C. Feng, Sumanta Chakraborty
The Weiss variation of the Einstein-Hilbert action with an appropriate boundary term has been studied for general boundary surfaces; the boundary surfaces can be spacelike, timelik…
The Life and Science of Thanu Padmanabhan
Jasjeet Singh Bagla, Krishnakanta Bhattacharya, Sumanta Chakraborty +21
Thanu Padmanabhan was a renowned Indian theoretical physicist known for his research in general relativity, cosmology, and quantum gravity. In an extraordinary career spanning fort…
Bouncing with shear: Implications from quantum cosmology
Karthik Rajeev, Vikramaditya Mondal, Sumanta Chakraborty
We consider the introduction of anisotropy in a class of bouncing models of cosmology. The presence of anisotropy often spells doom on bouncing models, since the energy density due…
Constraining extra dimensions using observations of black hole quasi-normal modes
Akash K Mishra, Abhirup Ghosh, Sumanta Chakraborty
The presence of extra dimensions generically modify the spacetime geometry of a rotating black hole, by adding an additional hair, besides the mass and the angular momentum …
Gravitational multipole moments for asymptotically de Sitter spacetimes
Sumanta Chakraborty, Sk Jahanur Hoque, Roberto Oliveri
We provide a prescription to compute the gravitational multipole moments of compact objects for asymptotically de Sitter spacetimes. Our prescription builds upon a recent definitio…