I study white dwarf stars and use them as cosmic laboratories to test ideas for dark matter
and dark energy, and to explore the equation of state of matter at high densities and
temperatures. I also uses them for cosmochronometry of the history of star formation in
our galaxy and its components.
A fraction of the white dwarfs are multiperiodic nonradial gravity mode pulsators. We use
the techniques of asteroseismology to study their deep interiors and observe their evolution.
A subset of these stars are the most stable optical clocks known. We search for variations in
the arrival time of the pulses indicating the presence of planets. In this way we can detect
gas and ice giant planets dynamically similar to those in the Solar System.