The result was keep. (non-admin closure) czar · · 23:50, 11 May 2013 (UTC)[reply]
Although slightly noted in relation to the full proof of the modularity theorem where he was one of several who extended Andrew Wiles famous proof, I can't find any evidence that this is not just "a routine professor of a subject at a university". Even his profile page doesn't seem to hint at more. He researches in his field and has a research fellowship by the American Mathematical Society, but there just doesn't seem to be enough here to suggest he is a notable academic in his own right in the sense of WP:N and WP:BIO.
I've considered the spirit of WP:ACADEMIC. While the modularity theorem is a major theorem, I don't think Diamond has been notable because of his involvement in it. From several angles the same conclusions - the theorem was largely a completion/extension of Wiles' historic work in 1995 which was based on Wiles' approaches and completed within some months (so he wasn't the "resolver of a major issue in number theory" at that point), and to underline this, a number of other researchers also seem to have published or collaborated in the same work's completion (see Modularity theorem#History). A check of third party reliable sources shows similarly that they haven't provided significant coverage of him in the sense a bio-article subject is usually discussed. Beyond that there's almost nothing else to draw on. As the guideline observes:
Eyeballs appreciated. FT2 (Talk | email) 19:45, 4 May 2013 (UTC)[reply]