Progress in warm dense matter and planetary physics

Abstract

We give an introduction into the method of quantum molecular dynamics simulations which combines density functional theory with classical molecular dynamics. This method has demonstrated its predictive power in determining the thermophysical properties of matter under extreme conditions as found, e.g., in astrophysical objects like giant planets and brown dwarfs. Such extreme states of matter can also be probed by state-of-the-art shock wave experiments in the laboratory. We give exemplary ab initio results for the behavior of the simplest and most abundant elements hydrogen and helium under extreme conditions. In addition, we also show results formore complex molecular systems such as water. The light elementsH and He, the hydrides of C (CH4), N (NH3), and O (H2O) and, in particular, mixtures of these systems have rich high-pressure phase diagrams which are important for the structure, evolution and magnetic field of gas giant planets like Jupiter and ice giant planets like Neptune. Finally, we describe the impact of these results on the design of advanced interior, evolution, and dynamo models and give exemplary results for solar and extrasolar giant planets.