Particle Astrophysics and Cosmology

Rainer Dick

Research in particle astrophysics at the University of Saskatchewan concentrates on two major puzzles of contemporary physics:
The Dark Matter Problem:
Astrophysical observations indicate that only about 10% of the matter in galaxies and galaxy clusters is composed of ordinary matter (essentially protons, neutrons, electrons and their bound states), but the rest of the matter bound in large scale structures in the universe must be composed of particles which cannot be produced in accelerators so far.

Since this matter component reveals itself only through its gravitational interactions, but does not produce luminous stars, it is denoted as dark matter.

One area of research that we pursue in this field is the investigation of particle physics candidates predicted by string theory and other extensions of the Standard Model of Particle Physics. We do this by calculating couplings, lifetimes and cosmic abundances of particle dark matter candidates, to test whether any of the candidates predicted by extensions of the standard model matches the requirements imposed by astrophysical observations.
The Origin of Ultra-high Energy Cosmic Rays:
Over the last decades several experiments observed cosmic rays of extremely high energies E> 1011 GeV. The northern hemisphere is hit by such extremely high energetic rays with a frequency of 1 event per 100 km2 per year, but reliable results from the southern hemisphere will only become available when the southern site of the Pierre Auger observatory in Argentina becomes fully operational. This is important, because both the galactic center and the closest galaxy cluster (the Virgo cluster) are only visible from the southern hemisphere.

The origin of these high-energetic cosmic rays is a puzzle for several reasons: In collaboration with colleagues from Fermilab I recently made the proposal that annihilation of extremely heavy dark matter particles can generate the ultra-high energy cosmic rays.

This proposal is attractive for several reasons: As a graduate student in my group you can participate in our ongoing efforts to unravel the mystery of the ultrahigh energy cosmic rays.

For more information please see my web page
or contact me by email: rainer.dick@usask.ca