The research to be conducted here centers around models for the structure and evolution of giant planets which can be used to relate observations of giant exoplanets to fundamental properties such as mass and radius. First, a modeling effort will be undertaken to compute the thermal evolution of young giant planets over a range of masses in a self-consistent way, i.e., coupled with core accretion models, rather than with the arbitrary initial conditions currently used. From these models, both spectra and colors will be calculated to allow for more accurate determinations of the masses of young objects found orbiting other stars. A second project will explore recent revisions in the equation of state for hydrogen to evaluate the corresponding changes in model radius. It is suggested that this change leads to larger radii at a given age and that the wide spread in radii seen among transiting extrasolar giant planets may be understood in terms of a large range in interior heavy element abundances versus the need for internal energy sources. This work will improve the return of future space missions to locate extrasolar planets as well as efforts from the ground by enabling more accurate determinations of basic properties from observations. The models here will also serve as a stepping stone to the eventual detection of Earth-like planets. The results of this work will be posted on the SETI Institute website and disseminated to the public through articles in popular journals.
