Theoretical Particle Physics and Cosmology – Niels Bohr Institute - University of Copenhagen

Theoretical Particle Physics and Cosmology

Our knowledge of the very smallest building bricks of the universe is explained in the Standard Model that describes the elementary particles and the three fundamental forces that are at work between them: 1. The electromagnetic forces that are responsible for the structure of atoms and molecules. 2. The weak nuclear forces that explain radio active fallout and the energy production of the stars. 3. The strong nuclear forces that describe the structure at quark level. However, there is a forth fundamental force in nature – gravity, and that the Standard Model cannot explain. Here it is necessary to combine the quantum mechanics with Einstein’s general theory of relativity, and that is extremely difficult.

The string theory is a theoretical model that tries to explain all fundamental forces, including gravitation. However, the mathematical calculations need more than the 3 spatial dimensions plus time as we know it. The model requires a further 9 dimensions where forces with huge energy create ‘super-strings’ that are invisible.

Cosmic background radiation eis electromagnetic radiation that originates from the creation of the universe 14 billion years ago. Because the background radiation goes back to the earliest phase of the universe it holds information about the laws of physics. The radiation is measured in micro waves and by studying them one can get fundamental new knowledge about the universe – from the elementary particles to the primary properties of the universe.

Black holes are gigantic stars that have collapsed to a massive compressed bloc of concentrated mass. When the star dies in a supernova-explosion the neutrons will normally force away each other because of the strong nuclear forces but the mass can be so heavy that gravitation wins and then the star shrinks into a black hole. New research using the model of the string theory shows that black rings exist as well.

Ekstra information / Sidebar