Pro ISSI talk

Abstract: The Universe is assumed to have started with a so-called “Big Bang”- a kind of enormous explosion in which particles and energy emerged. Subsequently, the Universe has cooled down and the structures, that we see today, have been forming. There are several independent indications for this being a good model for the Universe. Four of the main observational pilars of this model are presented and explained: Cosmic Microwave Background Radiation as a remnant of the Big Bang, the formation of Large-Scale Structure as traced by the galaxy distribution, the formation of light elements in the early Universe and the expansion of the Universe.

The expansion of the Universe suggests also an interesting question concerning the future of the Universe: Will the Universe expand forever or will it collapse eventually? To answer this question various components of the Universe are discussed, that act in a repelling and attracting way, respectively: Dark Energy and Dark Matter. Measurements using various independent methods show that there is a lot more Dark Matter in the Universe than the well known luminous matter consisting of atoms. But, nevertheless, there is obviously not enough matter in total (Dark Matter plus luminous matter) to stop the expansion. Observations indicate that the repellent component Dark Energy is outbalancing the attracting components, so that we obviously live in a Universe, in which the expansion will not only continue, but the expansion is even accelerating.