Citizens from many different countries can visit Norway without applying for a travel visa. Please check if you fall in this category on the website of the Norwegian Directorate of Immigration (UDI):
https://www.udi.no/en/want-to-apply/visit-and-holiday/

Beside the information whether you need a visa, the UDI website also informs you about required documents and estimated processing times for visa requests.

If your visa application requires an invitation letter or other documents from the conference, please contact us by email:
radiocarbon2018@videre.ntnu.no