While there's no publicly known author with the name "Biarne Castberg", it's possible there is a lesser-known author with that name. To find out more, you could:
* Search online book databases: Try searching for "Biarne Castberg" on sites like Goodreads or Amazon to see if any books appear under that name.
* Check university or research databases: If you have access to online academic databases, you could try searching for publications by that name.
* Ask in relevant forums: You could post a query in online forums related to writing, literature, or the specific genre you are interested in.
Please clarify if you have any other details about the author you're looking for, such as their genre, any specific books they might have written, or any other clues to their identity. This could help in finding the right author.