Ghost particles in the universe: Neutrinos in astrophysics and cosmology

Abstract

Neutrinos are nearly massless and very difficult to detect because they interact so very weakly. Sixty years after seeing the first of these «ghost particles» we know a lot about their properties. Today, observing them in nuclear reactors, the Sun, the Earth’s crust and atmosphere, and at high energies from distant cosmic sources is almost a routine task – they have become unique astrophysical messengers. They are important for a number of aspects: neutrinos shape some of the most dramatic astrophysical phenomena in the form of stellar-collapse supernova explosions, they may have created the excess of matter over antimatter in the universe, and neutrino-like «weakly interacting massive particles» may well account for the dark matter of the universe.

Keywords

• neutrinos
• dark matter
• supernova
• flavor oscillations
• astroparticle physics