David Fiske, Current Research Interests

I currently work with Prof. Charles Misner and Conrad Schiff in the Gravitation Theory Group at the University of Maryland, and with Prof. Pablo Laguna, Dr. Deirdre Shoemaker, Eric Schnetter, and Ken Smith in the Center for Gravitational Physics and Geometry at Penn State University.

Current projects:

Binary neutron star coalescence in scalar gravity (UMD)

In support of the pending science runs of LIGO we are attempting to calculate numerically the gravitational waves propagating out from a binary neutron star system in a scalar gravity model. We choose to work with scalar gravity rather than the full Einstein equations because a suitable scalar theory provides many of the features of the full theory while providing a numerically simpler testbed for dealing with problems associated with the suitable choice of initial conditions, enforcement of physical constraints, and matching of boundary conditions at the extraction radius.

Applied Science Fiction (UMD)

Applied Science Fiction is a name to a class of schemes which use "non-physical" physics to avoid numerical problems in physical solutions. So long as the effects of non-physical aspects of a numerical model do not propagate into a region of space or time where true physical results are desired, they cause no problem in making correct physical predictions. On the other hand, such schemes may help avoid numerical problems, the physical singularity at the center of a black hole, for example, and thus make simulations more stable. We are currently seeking ASF alternatives to excision in 3+1 numerical relativity codes.

Numerical evolution of black hole spacetimes (PSU)

As guest with the numerical relativity group at the Penn State University Center for Gravitational Physics and Geometry, I am working on numerical codes in the ADM formalism for long-term stable evolution of single black hole spacetimes. The current code is known as Maya.

Application of Lie algebraic mapping techniques to GR (UMD)

From my previous experience with the University of Maryland Dynamical Systems and Accelerator Theory Group, I have some knowledge of how Lie algebraic methods have been fruitfully applied to Newtonian mechanics. As part of my current work in GR, I am looking at ways to generalize these methods for use in full GR and for ways to apply techniques already developed by the accelerator design community to problems of numerical relativity.