[1] He received a cand.mag degree from the University of Bergen with the subjects mathematics, literature and religion.

[3][4] Stubhaug made his literary debut in 1970 with the poetry collection Utkantane.

Further poetry collections are Du ber vatn i hendene from 1973, Eld i sol from 1988, and Lemmata from 2008.

[3] He has written biographies of the mathematicians Sophus Lie, Niels Henrik Abel and Gösta Mittag-Leffler,[3] Jacob Aall, Conrad Nicolai Schwach [no], and Stein Rokkan.

Niels Henrik Abel og hans tid,[5] translated into English under the title Niels Henrik Abel and his Times: Called Too Soon by Flames Afar, He followed up with the 250-year history of the Royal Norwegian Society of Sciences and Letters (2010) and biographies of Jacob Aall (2014) and the social scientist Stein Rokkan (2019).