It’s not a “study”, it’s just 2 mathematicians having some fun. The paper is a good read, and as a math teacher I see a lot of pedagogical values in such publications.

It’s pronounced as one syllable in the Nordic languages

I don’t think vinyls are hipster. In the age of music digitalization, it is nice to own a physical piece of media, in addition to being able to support your artist more directly. Also it looks nice.