Today's puzzle was constructed by Brendan! Happy solving!

Brendan says: "This puzzle is themed around an applied mathematician whose birthday is today. Not only are they an interesting and influential scientist, but I bet their first / last names could be useful to y'all as crossword fill! If you're interested in more puzzles that feature mathematical people, concepts, and terminology, check out my book. I also share (non-math) crosswords on my blog."