12 research outputs found
Numerical investigation of the dynamics of linear spin fields on Kerr background I. Late time tails of spin fields
The time evolution of linear fields of spin and on
Kerr black hole spacetimes are investigated by solving the homogeneous
Teukolsky equation numerically. The applied numerical setup is based on a
combination of conformal compactification and the hyperbolic initial value
problem. The evolved basic variables are expanded in terms of spin-weighted
spherical harmonics which allows us to evaluate all the angular derivatives
analytically, whereas the evolution of the expansion coefficients, in the
time-radial section, is determined by applying the method of lines implemented
in a fourth order accurate finite differencing stencil. Concerning the
initialization, in all of our investigations single mode excitations---either
static or purely dynamical type initial data---are applied. Within this setup
the late time tail behavior is investigated. Due to the applied conformal
compactification the asymptotic decay rates are determined at three
characteristic locations---in the domain of outer communication, at the event
horizon and at future null infinity---simultaneously. Recently introduced new
type of `energy' and `angular momentum' balance relations are also applied in
order to demonstrate the feasibility and robustness of the developed numerical
schema, and also to verify the proper implementation of the underlying
mathematical model.Comment: 38 pages, 5 figures, typos correcte
Is it possible to construct asymptotically flat initial data using the evolutionary forms of the constraints?
Near-Kerr black hole initial datasets are constructed by applying either the
parabolic-hyperbolic or the algebraic-hyperbolic form of the constraints. In
both cases, strongly and weakly asymptotically flat initial datasets with
desirable falloff rates are produced by controlling only the monopole part of
one of the freely specifiable variables. The viability of the applied method is
verified by numerically integrating the evolutionary forms of the constraint
equations in the case of various near-Kerr configurations.Comment: 43 pages, 6 figure
Lineáris perturbációk és a kényszeregyenletek megoldásainak numerikus vizsgálata az általános relativitáselméletben
Numerical investigation of the dynamics of linear spin s fields on a Kerr background: Late-time tails of spin s=±1,±2 fields
Magyar Tanítóképző 40 (1927) 6
Magyar Tanítóképző
A Tanítóképző-intézeti Tanárok Országos Egyesületének folyóirata
40. évfolyam, 6. szám
Budapest, 1927. júniu
Magyar Tanítóképző 41 (1928) 3
Magyar Tanítóképző
A Tanítóképző-intézeti Tanárok Országos Egyesületének folyóirata
41. évfolyam, 3. szám
Budapest, 1928. máju
Magyar Tanítóképző 45 (1932) 6
Magyar Tanítóképző
A Tanítóképző-intézeti Tanárok Országos Egyesületének folyóirata
45. évfolyam, 6. szám
Budapest, 1932. júniu
Numerical investigation of the dynamics of linear spin fields on a Kerr background II: Superradiant scattering
Superradiant scattering of linear spin fields on Kerr black
hole background is investigated in the time domain by integrating numerically
the homogeneous Teukolsky master equation. The applied numerical setup has
already been used in studying long time evolution and tail behavior of
electromagnetic and metric perturbations on rotating black hole background
[arXiv:1905.09082v3]. To have a clear setup the initial data is chosen to be of
the compact support, while to optimize superradiance the frequency of the
initial data is fine tuned. Our most important finding is that the rate of
superradiance strongly depends on the relative position of the (compact)
support of the initial data and the ergoregion. When they are well-separated
then only a modest -- in case of scalar fields negligible --
superradiance occurs, whereas it can get to be amplified significantly whenever
the support of the initial data and the ergoregion overlap.Comment: 45 pages, 26 figure