Results for "Shourya Khanna"
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Battery and Dynamo theory in the Kerr metricApr 16 1999The generation and evolution of magnetic fields in the plasma accreting into a rotating black hole is studied in the 3+1 split of the Kerr metric. Attention is focused on effects of the gravitomagnetic potential. The gravitomagnetic force appears as battery ... More Collision of spinning black holes in the close limitJan 03 2001In this paper we consider the collision of spinning holes using first order perturbation theory of black holes (Teukolsky formalism). With these results (along with ones, we published in the past) one can predict the properties of the gravitational waves ... More Sensitivity and Computational Complexity in Financial NetworksMar 26 2015Oct 25 2016Modern financial networks exhibit a high degree of interconnectedness and determining the causes of instability and contagion in financial networks is necessary to inform policy and avoid future financial collapse. In the American Economic Review, Elliott, ... More A self-regulated model of galactic spiral structure formationMay 22 2001Feb 19 2002The presence of spiral structure in isolated galaxies is a problem that has only been partially explained by theoretical models. Because the rate and pattern of star formation in the disk must depend only on mechanisms internal to the disk, we may think ... More Sensitivity and Computational Complexity in Financial NetworksMar 26 2015Modern financial networks exhibit a high degree of interconnectedness and determining the causes of instability and contagion in financial networks is necessary to inform policy and avoid future financial collapse. In the American Economic Review, Elliott, ... More Wave functions for the Schwarschild black hole interiorFeb 07 2006Apr 08 2006Using the Hamiltonian constraint derived by Ashtekar and Bojowald, we look for pre-classical wave functions in the Schwarzschild interior. In particular, when solving this difference equation by separation of variables, an inequality is obtained relating ... More Brief note on high-multipole Kerr tailsDec 18 2013Jan 19 2015In this note we reconsider the late-time, power-law decay rate of scalar fields in a Kerr space-time background. We implement a number of mathematical and computational enhancements to our time-domain, (2+1)D Teukolsky evolution code and are able to obtain ... More Randomized Composable Coresets for Matching and Vertex CoverMay 23 2017A common approach for designing scalable algorithms for massive data sets is to distribute the computation across, say $k$, machines and process the data using limited communication between them. A particularly appealing framework here is the simultaneous ... More Approximate pre-classical solutions in loop quantum cosmologySep 20 2005In this paper we introduce a numerical approximation technique to obtain pre-classical solutions to models of loop quantum gravity. In particular, we apply the technique to vacuum Bianchi I cosmological models and recover known solutions. We also present ... More Separable sequences in Bianchi I loop quantum cosmologyJun 05 2005Oct 18 2005In this paper, we discuss the properties of one-parameter sequences that arise when solving the Hamiltonian constraint in Bianchi I loop quantum cosmology using a separation of variables method. In particular, we focus on finding an expression for the ... More Delays and the Capacity of Continuous-time ChannelsMay 17 2011Any physical channel of communication offers two potential reasons why its capacity (the number of bits it can transmit in a unit of time) might be unbounded: (1) Infinitely many choices of signal strength at any given instant of time, and (2) Infinitely ... More The K2-HERMES Survey: Age and Metallicity of the Thick DiscApr 29 2019Asteroseismology is a promising tool to study Galactic structure and evolution because it can probe the ages of stars. Earlier attempts comparing seismic data from the {\it Kepler} satellite with predictions from Galaxy models found that the models predicted ... More Weak axial exchange currents for the Bethe-Salpeter equationNov 05 1999Nov 06 1999We construct weak axial one-boson exchange currents for the Bethe-Salpeter equation, starting from chiral Lagrangians of the N-\Delta(1236)-pi-rho-a_1-omega system. The currents fulfil the Ward-Takahashi identities and the matrix element of the full current ... More Late-time Kerr tails revisitedNov 06 2007Mar 19 2008The decay rate of late time tails in the Kerr spacetime have been the cause of numerous conflicting results, both analytical and numerical. In particular, there is much disagreement on whether the decay rate of an initially pure multipole moment ${\ell}$ ... More On the Restricted Isometry of the Columnwise Khatri-Rao ProductSep 18 2017Jul 24 2018The columnwise Khatri-Rao product of two matrices is an important matrix type, reprising its role as a structured sensing matrix in many fundamental linear inverse problems. Robust signal recovery in such inverse problems is often contingent on proving ... More Controllable coherent perfect absorption in a composite filmNov 18 2011We exploit the versatility provided by metal--dielectric composites to demonstrate controllable coherent perfect absorption (CPA) in a slab of heterogeneous medium. The slab is illuminated by coherent light from both sides, at the same angle of incidence ... More von Neumann Lattices in Finite Dimensions Hilbert SpacesMay 07 2008The prime number decomposition of a finite dimensional Hilbert space reflects itself in the representations that the space accommodates. The representations appear in conjugate pairs for factorization to two relative prime factors which can be viewed ... More Creation of Digital Test Form for Prepress DepartmentSep 23 2012The main problem in colour management in prepress department is lack of availability of literature on colour management and knowledge gap between prepress department and press department. So a digital test from has been created by Adobe Photoshop to analyse ... More $Λ^+_c$- and $Λ_b$-hypernucleiJul 26 2002Dec 09 2002$\Lambda^+_c$- and $\Lambda_b$-hypernuclei are studied in the quark-meson coupling (QMC) model. Comparisons are made with the results for $\Lambda$-hypernuclei studied in the same model previously. Although the scalar and vector potentials felt by the ... More Radiative falloff in the background of rotating black holeSep 27 2002Mar 06 2003We study numerically the late-time tails of linearized fields with any spin $s$ in the background of a spinning black hole. Our code is based on the ingoing Kerr coordinates, which allow us to penetrate through the event horizon. The late time tails are ... More On radiative muon capture in hydrogenFeb 02 2001Nov 22 2001We analyze photon spectra in the radiative muon capture in hydrogen using amplitudes derived from chiral Lagrangians. The model can describe the high energy part of the photon spectra, measured recently at TRIUMF, reasonably well. Black Hole Ringing, Quasinormal Modes, and Light RingsSep 01 2016Sep 11 2016Modelling of gravitational waves from binary black hole inspiral has played an important role in the recent observations of such signals. The late-stage ringdown phase of the gravitational waveform is often associated with the null particle orbit ("light ... More Image Classification and Optimized Image ReproductionSep 23 2012By taking into account the properties and limitations of the human visual system, images can be more efficiently compressed, colors more accurately reproduced, prints better rendered. To show all these advantages in this paper new adapted color charts ... More Masses of Heavy HadronsMay 09 2000An estimate has been made of the masses of heavy hadrons in nonrelativistic quark model, which includes spin and flavor-dependent hyperfine splitting for two quarks. The effect of variation of the wavefunction value at origin and the strong coupling constant, ... More Mode coupling mechanism for late-time Kerr tailsDec 18 2013We consider the decay rate for scalar fields in Kerr spacetime. We consider pure initial (azimuthal) multipoles $\ell'$ with respect to the class which includes Boyer-Lindquist coordinates, and focus attention on the decay rate of the multipole $\ell$. ... More Massive scalar field instability in Kerr spacetimeDec 05 2004We study the Klein-Gordon equation for a massive scalar field in Kerr spacetime in the time-domain. We demonstrate that under conditions of super-radiance, the scalar field becomes unstable and its amplitude grows without bound. We also estimate the growth ... More Quantum Gravity in D=5 DimensionsJun 16 2000Jun 22 2000We propose a topological Chern-Simons term in D=5 dimensions coupled to Einstein Hilbert theory. Hartree approximation for topological Lagrangian and the Chern-Simons term in D=3 is considered. An effective model of Quantum Gravity in D=5 dimensions is ... More The GALAH Survey: Chemodynamics of the Solar NeighbourhoodJan 22 2019We present the chemodynamic structure of the solar neighbourhood using 62 814 stars within a 500 pc sphere of the Sun observed by GALAH and with astrometric parameters from Gaia DR2. We measure the velocity dispersion for all three components (vertical, ... More Cauchy-horizon singularity inside perturbed Kerr black holesJan 19 2016The Cauchy horizon inside a perturbed Kerr black hole develops an instability that transforms it into a curvature singularity. We solve for the linearized Weyl scalars $\psi_0$ and $\psi_4$ and for the curvature scalar $R_{\alpha\beta\gamma\delta}R^{\alpha\beta\gamma\delta}$ ... More Intermediate behavior of Kerr tailsAug 29 2012Feb 17 2014The numerical investigation of wave propagation in the asymptotic domain of Kerr spacetime has only recently been possible thanks to the construction of suitable hyperboloidal coordinates. The asymptotics revealed an apparent puzzle in the decay rates ... More Streaming Lower Bounds for Approximating MAX-CUTSep 07 2014We consider the problem of estimating the value of max cut in a graph in the streaming model of computation. At one extreme, there is a trivial $2$-approximation for this problem that uses only $O(\log n)$ space, namely, count the number of edges and ... More Social Welfare in One-sided Matching Markets without MoneyApr 15 2011We study social welfare in one-sided matching markets where the goal is to efficiently allocate n items to n agents that each have a complete, private preference list and a unit demand over the items. Our focus is on allocation mechanisms that do not ... More Distributed Private Heavy HittersFeb 22 2012Nov 06 2014In this paper, we give efficient algorithms and lower bounds for solving the heavy hitters problem while preserving differential privacy in the fully distributed local model. In this model, there are n parties, each of which possesses a single element ... More