3 citations · 12 across the 18 of their papers we have counts for
18 papers
Cosmological Evolution of Primordial Black Holes: UV/IR Decoupling and the KM3NeT 220 PeV Neutrino Anomaly
Debdatta Dey, Tausif Parvez, S. Shankaranarayanan
The recent observation of a 220 PeV neutrino event (KM3-230213A) by the KM3NeT observatory presents a formidable challenge to standard astrophysical source models. We investigate t…
Integrated cosmological memory: A dark-siren method to probe dark energy
Indranil Chakraborty, Sayantan Ghosh, Susmita Jana +2
Gravitational-wave (GW) cosmology is currently bottlenecked by the scarcity of electromagnetic counterparts for bright sirens and the systematic uncertainties of galaxy catalogs fo…
A non-local origin for massive gravity and late-time acceleration
Susobhan Mandal, S. Shankaranarayanan
The accelerated expansion of the universe poses a significant challenge to General Relativity. Non-local modifications to gravity have emerged as a compelling class of theories to…
Exact, non-singular black holes from a phantom DBI Field as primordial dark matter
Tausif Parvez, S. Shankaranarayanan
We present the first exact, non-singular black hole solution in General Relativity sourced by a Dirac-Born-Infeld (DBI) scalar field. Crucially, the solution is exclusively support…
Disformal interactions in the Dark Sector: From driving Early Dark Energy to confronting cosmological tensions
Pulkit Bansal, Joseph P. Johnson, S. Shankaranarayanan
The CDM model faces significant challenges, including an incomplete understanding of the dark sector and persistent tensions in the Hubble constant and the clustering amplitude.…
Quantum signatures in black hole accretion: Pair production in dynamical magnetic fields
Susobhan Mandal, Tausif Parvez, S. Shankaranarayanan
Accretion disks around black holes host extreme conditions where general relativity and magnetohydrodynamics dominate. These disks exhibit two distinct dynamical regimes -- Standar…
Signatures of asymmetry: Gravitational wave memory and the parity violation
Indranil Chakraborty, Susmita Jana, S. Shankaranarayanan
Einstein's equivalence principle suggests a deep connection between matter and spacetime, prompting the question: if matter violates parity, must gravity? This letter explores the…
Modified theories of gravity at different curvature scales
Susobhan Mandal, S. Shankaranarayanan
General Relativity (GR) remains the cornerstone of gravitational physics, providing remarkable success in describing a wide range of astrophysical and cosmological phenomena. Howev…
Can Q-balls describe cosmological and galactic dark matter?
Susobhan Mandal, S. Shankaranarayanan
The Cold Dark Matter (CDM) hypothesis accurately predicts large-scale structure formation and fits the Cosmic Microwave Background temperature fluctuations (CMB). However, observat…
Analog charged black hole formation via percolation: Exploring cosmic censorship and Hoop conjecture
Nitesh Jaiswal, S. Shankaranarayanan
We investigate an analog model of charged black hole (BH) formation using the framework of classical percolation. By analyzing the scaling behavior of key quantities, including sur…
Scalar quasinormal modes in emergent modified gravity
Martin Bojowald, Erick I. Duque, S. Shankaranarayanan
Emergent modified gravity is a post-Einsteinian gravitational theory where spacetime geometry is not fundamental but rather emerges from the gravitational degrees of freedom in a n…
Interacting dark sector from Horndeski theories and beyond: Mapping fields and fluids
Pulkit Bansal, Joseph P Johnson, S. Shankaranarayanan
In Cosmology, when dissipative effects are minimal, the energy content of the Universe can be effectively described as a sum of perfect fluids. Perfect fluid descriptions ensure th…
Generation of effective massive Spin-2 fields through spontaneous symmetry breaking of scalar field
Susobhan Mandal, S. Shankaranarayanan
General relativity and quantum field theory are the cornerstones of our understanding of physical processes, from subatomic to cosmic scales. While both theories work remarkably we…
Prospects for cosmological constraints using gravitational wave memory
Indranil Chakraborty, Susmita Jana, S. Shankaranarayanan
The ΛCDM model has long served as a robust and predictive framework for cosmology, successfully explaining a wide range of observations, including the accelerated expansion of the…
Dynamical 4-D Gauss-Bonnet action from matter-graviton interaction at one-loop
Susobhan Mandal, S. Shankaranarayanan
The occurrence of singularities at the centers of black holes suggests that general relativity (GR), although a highly successful model of gravity and cosmology, is inapplicable. T…
Transient electromagnetic sources can detect solitary black holes in Milky Way galaxy
Susmita Jana, Rituparno Goswami, S. Shankaranarayanan +1
The Milky Way galaxy is estimated to host up to a billion stellar-mass solitary black holes (BHs). The number and distribution of BH masses can provide crucial information about th…
From Horndeski action to the Callan-Giddings-Harvey-Strominger model and beyond
Susobhan Mandal, Tausif Parvez, S. Shankaranarayanan
The knowledge of what entered black hole (BH) is completely lost as it evaporates. This contradicts the unitarity principle of quantum mechanics and is referred to as the informati…
A test of Einstein's equivalence principle in future VLBI observations
Joseph P Johnson, Susmita Jana, S. Shankaranarayanan
We show that very-long-baseline-interferometry (VLBI) observations of supermassive black holes will allow us to test the fundamental principles of General Relativity (GR). GR is ba…