WIMP -
a hypothetical subatomic particle of large mass that interacts weakly with ordinary matter through gravitation; postulated as a constituent of the dark matter of the universe
dark matter (cosmology) a hypothetical form of matter that is believed to make up 90 percent of the universe; it is invisible (does not absorb or emit light) and does not collide with atomic particles but exerts gravitational force
natural philosophy,
physics the science of matter and energy and their interactions; "his favorite subject was physics"