– University of Copenhagen

Astroparticle physics and cosmology

Astroparticle physics and cosmology pose some of the most fundamental questions in science:

  • What is the nature of dark matter which accounts for about 80% of the mass in the Universe but the existence of which is inferred only through its gravitational interactions?

  • What is the nature of the dark energy, presumed to be driving the apparent accelerated expansion of the Universe?

  • Did the very early Universe undergo a phase of exponentially fast expansion - inflation - during which quantum fluctuations created the density perturbations that later grew into the observed large-scale structure of galaxies?

  • What is accelerating charged particles to the extreme energies observed in astrophysical sources of gamma-rays and neutrinos?

In the Theoretical Particle Physics & Cosmology group we are tackling these astroparticle questions from different angles, exploring the interfaces with both particle physics and astrophysical models of the high-energy Universe. While our work is mainly theoretical it must be tested against observational data. To this end, we are also involved in a number of experimental efforts:

  • Data from the Planck satellite provide important constraints on the non-gravitational interactions of dark matter in the early Universe.

  • We use data from supernova surveys and other cosmological observations to test fundamental issues e.g. the isotropy of the universe and if the Hubble expansion rate is indeed accelerating.

  • The planned DeepSpace experiment in Greenland will look for gravitational waves from inflation, imprinted into the CMB as a characteristic polarisation pattern.

  • We are involved with IceCube, a giant cubic kilometer detector buried under the South Pole, which detects high energy neutrinos that inform our understanding of the sources of the high energy cosmic rays.

For more information on astroparticle physics research at NBI visit the Astroparticle Physics Group's webpage, in particular the list of downloadable publications.