He has been a visiting scientist at the Max Planck Institute for Gravitational Physics and the Friedrich Schiller University, both in Germany, and the Institut des Hautes Etudes Scientifiques, France. He currently works in the field of gravitational-wave data analysis and general-relativistic problem of motion. Andrzej Krolak is a Professor in the Institute of Mathematics at the Polish Academy of Sciences, Poland. He has twice been awarded the Second Prize by the Gravity Research Foundation (once with Bernard Schutz). He has been a visiting scientist at the Max Planck Institute for Gravitational Physics, Germany, and the Jet Propulsion Laboratory, USA. His field of research is gravitational-wave theory data analysis and general theory of relativity, and the phenomena predicted by this theory such as black holes and gravitational waves.