203 citations · 3.4k across the 107 of their papers we have counts for
14 papers · 1 filter
A comment on generalized Schwinger effect
Karthik Rajeev, Sumanta Chakraborty, T. Padmanabhan
A spatially homogeneous, time-dependent, electric field can produce charged particle pairs from the vacuum. When the electric field is constant, the mean number of pairs which are…
Inverting a normal harmonic oscillator: Physical interpretation and applications
Karthik Rajeev, Sumanta Chakraborty, T. Padmanabhan
A harmonic oscillator with time-dependent mass and a time-dependent (squared) frequency occurs in the modelling of several physical systems. It is generally believe…
Horndeski theories confront the Gravity Probe B experiment
Sajal Mukherjee, Sumanta Chakraborty
In this work we have investigated various properties of a spinning gyroscope in the context of Horndeski theories. In particular, we have focused on two specific situations --- (a)…
Decoding infrared imprints of quantum origins of black holes
Sumanta Chakraborty, Kinjalk Lochan
We analyze the emission spectrum of a (fundamentally quantum) black hole in the Kerr-Newman family by assuming a discretization of black hole geometry and the holographic entropy-a…
Signatures of extra dimensions in gravitational waves from black hole quasi-normal modes
Sumanta Chakraborty, Kabir Chakravarti, Sukanta Bose +1
In this work we have derived the evolution equation for gravitational perturbation in four dimensional spacetime in presence of a spatial extra dimension. The evolution equation is…
On the physical process first law for dynamical black holes
Akash Mishra, Sumanta Chakraborty, Avirup Ghosh +1
Physical process version of the first law of black hole mechanics relates the change in entropy of a perturbed Killing horizon, between two asymptotic cross sections, to the matter…
Packing extra mass in compact stellar structures: An interplay between Kalb-Ramond field and extra dimensions
Sumanta Chakraborty, Soumitra SenGupta
We have derived the Buchdahl's limit for a relativistic star in presence of the Kalb-Ramond field in four as well as in higher dimensions. It turns out that the Buchdahl's limit ge…
Excavating black hole continuum spectrum: Possible signatures of scalar hairs and of higher dimensions
Indrani Banerjee, Sumanta Chakraborty, Soumitra SenGupta
Continuum spectrum from black hole accretion disc holds enormous information regarding the strong gravity regime around the black hole and hence about the nature of gravitational i…
Cosmological implications of shift symmetric Galileon field
Rabin Banerjee, Sumanta Chakraborty, Arpita Mitra +1
A ghost-free metric formulation of the recently proposed covariant Galileon model \cite{RPgal} which retains the internal shift symmetry has been constructed. This presents a new r…
Field equations for Lovelock gravity: An alternative route
Sumanta Chakraborty
We present an alternative derivation of the gravitational field equations for Lovelock gravity starting from the Newton's law, which is closer in spirit to the thermodynamic descri…
A Novel Derivation of the Boundary Term for the Action in Lanczos-Lovelock Gravity
Sumanta Chakraborty, Krishnamohan Parattu, T. Padmanabhan
We present a novel derivation of the boundary term for the action in Lanczos-Lovelock gravity, starting from the boundary contribution in the variation of the Lanczos-Lovelock acti…
Entropy of a box of gas in an external gravitational field revisited
Sourav Bhattacharya, Sumanta Chakraborty, T. Padmanabhan
Earlier it was shown that the entropy of an ideal gas, contained in a box and moving in a gravitational field, develops an area dependence when it approaches the horizon of a stati…
Black Holes: Eliminating Information or Illuminating New Physics?
Sumanta Chakraborty, Kinjalk Lochan
Black holes, initially thought of as very interesting geometric constructions of nature, over time, have learnt to (often) come up with surprises and challenges. From the era of be…
Gravity stabilizes itself
Sumanta Chakraborty, Soumitra SenGupta
We show that a possible resolution to the stabilization of an extra spatial dimension (radion) can be obtained solely in the context of gravitational dynamics itself without the ne…