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Dr. Sascha Husa
Address: Max-Planck-Institut für Gravitationsphysik
Albert-Einstein-Institut

Am Mühlenberg 1
14476 Golm
Phone: +49 (331) 567-
Fax: +49 (331) 567-
Office:
E-mail: Firstname.Lastname@aei.mpg.de
Personal Page: http://www.aei.mpg.de/~shusa/

Research Interests

Research Interests

My present work at the AEI focuses on numerical methods to solve the conformal field equations of general relativity. These equations constitute an approach invented by H. Friedrich, where the idea of conformal compactification (pioneered by Penrose) is taken to the level of the field equations. By a judicious choice of (conformally rescaled) variables Friedrich derived a system of PDEs, which is regular even beyond null infinity. For an overview see e.g. the recent Living Review article of Jörg Frauendiener. More specifically I plan to extend previous work of Peter Hübner towards asymptotically Minkowskian situations with strong gravity.

Another interest ist the characteristic approach to numerical relativity. Here I contribute to the program centered at the Pittsburgh numerical relativity group. In particular I am interested in the geometry of event horizons and perturbation theory. For sample publications see:

Roberto Gomez, Sascha Husa, Jeffrey Winicour: Complete null data for a black hole collision (gr-qc/0009092)
Sascha Husa and Jeffrey Winicour: The Asymmetric Merger of Black Holes, Phys.Rev. D60 (1999) 084019 (gr-qc/9905039)

A lot of interesting physics can be learned from very simple, even spherically symmetric systems. Lots of exciting results have been obtained on critical phenomena associated with black hole formation in self-gravitating systems. In collaboration with colleagues from the U Vienna relativity group I hope to find out a bit more about critical phenomena in gravitating nonlinear sigma models. First results are available as

Sascha Husa, Christiane Lechner, Michael Pürrer, Jonathan Thornburg, Peter C. Aichelburg, Type II Critical Collapse of a Self-Gravitating Nonlinear sigma-Model, Physical Review D 62(10), 104007 (gr-qc/0002067)

Earlier work has been concerned with gravitating solitons and conformal compactification methods for the solution of the GR constrains on asymptotically flat Cauchy surfaces, for sample publications on the latter topic see:

Sascha Husa, Initial Data for General Relativity Containing a Marginally Outer Trapped Torus, Phys. Rev. D54 (1996) 7311 (gr-qc/9606042)
Robert Beig and Sascha Husa, Initial Data for General Relativity with Toroidal Conformal Symmetry, Phys. Rev. D50 (1994) 7116 (gr-qc/9410003)