  The evolution of white dwarfs is essentially a gravothermal process of
cooling in which the basic ingredients for predicting their evolution are well
identified, although not always well understood. There are two independent ways
to test the cooling rate. One is the luminosity function of the white dwarf
population, and another is the secular drift of the period of pulsation of
those individuals that experience variations. Both scenarios are sensitive to
the cooling or heating time scales, for which reason, the inclusion of any
additional source or sink of energy will modify these properties and will allow
to set bounds to these perturbations. These studies also require complete and
statistical significant samples for which current large data surveys are
providing an unprecedented wealth of information. In this paper we review how
these techniques are applied to several cases like the secular drift of the
Newton gravitational constant, neutrino magnetic moments, axions and weakly
interacting massive particles (WIMPS).
