Before you go to the Danish Diplomatic Mission to apply for a visa, you have to get an invitation called VF2 completed by International Staff Office at SDU. International Staff Office employee Luna Kyung Keller Larsen is responsible for the visa invitations at SDU, and she can be contacted at: luna@sdu.dk or +45 6550 1947.
You also have to get an official invitation signed by the host (the person that invites you to SDU), as this is something the Danish Diplomatic Missions wants to see because they compare it with the VF2-invitation. Luna can guide the Department at SDU about, what the invitation letter should include.
If you have got any questions about the short-term visa application, you are welcome to contact Luna at luna@sdu.dk or +45 6550 1947.