ASTR-1010 Lecture Notes - Lecture 11: Dark Matter, Accelerating Expansion Of The Universe, Gravitational Lens
6 Oct 2016
School
Department
Course
Professor
Document Summary
Gravity of dark matter is what caused protogalactic clouds to contract early in time. Wimps can"t contract to center because they don"t radiate away their orbital energy. Dark matter is still pulling things together. After correcting for hubble"s law, we can see that galaxies are flowing toward the densest regions of space. Maps of galaxy positions reveal extremely large structures: superclusters and voids. Models show that gravity of dark matter pulls mass into denser regions universe grows lumpier with time. There is so much dark matter that the luminous matter that we can see into those big unseen but felt dark matter areas. Structures in galaxy maps look very similar to the ones found in models in which dark matter is wimps. Will the universe continue expanding forever: recollapsing universe. Lots of dark matter: critical/flat universe. Fate of unverse depends on the amount of dark matter.
