According to the APA style manual, the editorial "we" is used to refer to the author and co-authors but should not be used if there is a single author. However, in writing my mathematics thesis, I am working closely with a professor to do the research. He won't be listed as an author as far as I'm aware, but it feels natural to use the pronoun "we" to talk about results found during or after a proof. It also has always seemed more a reference to the author and reader together but perhaps this has only been my own erroneous imagination. Here is the link to the APA style reference I mentioned: https://apastyle.apa.org/style-grammar-guidelines/grammar/first-person-pronouns
Should I avoid using the pronoun "we?"