Ab initio description of warm dense matter applied to the physics of giant planets

Abstract Today, more than 6000 exoplanets are known after the first detection of an extrasolar planet around a main sequence star in 1995. Among them are representatives of new planetary classes such as Super-Earths and Mini-Neptunes, in addition to those already known from the solar system: rocky planets (Mercury, Earth, Venus, Mars), gas giants (Jupiter, Saturn), and ice giants (Uranus, Neptune). In order to understand the formation of planets, their interior structure and composition, thermal evolution and magnetic field, precise data on the equation of state, the transport coefficients, and the optical properties of the most abundant planetary materials are necessary. Relevant temperatures and densities cover a wide range from cold and dilute molecular clouds or planetary atmospheres up to warm and dense planetary cores. Ab initio simulations allow to determine thermophysical properties of warm dense matter with high precision. In this review we give an introduction into the ab initio methods and demonstrate their capacity for planetary physics by showing exemplary results for the thermophysical properties of key materials such as H-He (gas giants) and H-C-N-O mixtures (ice giants). Based on these results, advanced models for the interior structure of planets, their thermal evolution, and their magnetic field can be developed.