Ian Hinder - Postdoctoral Scholar
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Physical Address:301D Whitmore Laboratory |
Mailing Address:The Pennsylvania State University |
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Research Interests
Mode coupling and black hole spectroscopy
The inspiral and merger of two black holes in a binary system is expected to be a strong source of gravitational radiation. When the two holes merge, they form a singledistorted black hole which quickly settles down to the Kerr type. We are interested in understanding the form of the gravitational radiation that can be emitted by the single distorted black hole before it settles down, and how the different modes of the radiation might be coupled to each other by the black hole spacetime.
In order to simulate a highly distorted black hole without the computational cost of performing a binary black hole evolution, we distort a Kerr black hole using a strong pulse of gravitational radiation. The gravitational wave starts off at a long distance from the black hole and travels inwards. As the wave interacts with the spacetime around the black hole, some of the energy from the wave is absorbed, and some is re-radiated (note that the wave is scattered off the spacetime potential surrounding the black hole, there is no radiation from the black hole event horizon itself). Similarly, angular momentum from the incoming wave can be transferred to the black hole, causing it to change its spin. The black hole will now no longer be Kerr; it will be a distorted black hole.
By studying the waves emitted by the distorted black hole, we hope to learn about the final stages of the binary black hole merger process. The figure shows a Teukolsky wave travelling inward towards a Schwarzschild black hole.
Kranc - Automated code generation
I work with Sascha Husa and Christiane Lechner on the Kranc Mathematica package. This package was written by us, and allows you to automatically generate computer code for solving time evolution partial differential equations numerically using the Cactus infrastructure, in a fraction of the time it would take to write such a system by hand. The first version has been released, and is available under the GPL licence for anyone to use. See the paper Kranc: a Mathematica application to generate numerical codes for tensorial evolution equations.
Kranc allows us to automatically generate simulation code for the complicated Einstein equations; the distorted black hole simulations are being performed with Kranc-generated code. We are currently extending the system to allow the user to specify advanced customizable boundary conditions.
