Bergström has worked at the interface of particle physics, astrophysics and cosmology. He has collaborated in numerous international experiments, including AMANDA, IceCube and Fermi. His contributions have been exceptionally important in the field of dark matter indirect detection, through the search of annihilation products of dark matter in the Universe. Together with Paolo Gondolo, Joakim Edsjö, Piero Ullio, Mia Schelke and Edward Baltz, he developed DarkSUSY, a famous numerical package for neutralino dark matter calculations. Bergström has also contributed importantly to the field of supersymmetry, particularly studying supersymmetric dark matter candidates. Bergström has published over 100 papers in peer-reviewed journals.