Gregorius is currently working within the research project Back to Blood: Pursuing a Future from the Norse Past, a research collaboration between Linköping University and University of Stavanger, Norway. The project is funded by the Norwegian Research Council. His project is titled: The Landscape of the gods: Negotiating the role of place and meaning in Viking archaeological sites and museums and deals with how places associated with Old Norse religion have been used throughout history.
More information about the project Bad Blood
Apart from this has Gregorius primarily conducted research on apocalyptic Christian movements in the United States, modern Satanism and neo-Paganism. This research has been oriented towards the reception of religious concepts and how these have changed over time and place, due to political and social motives.