there's gotta be something weird going on here. either they are rolling "tuition" waivers into this, or they are quoting salaries for 40 hours but the actual positions are paid at 20 hours (on paper).

as a more typical example, the University of Illinois offers somehwere around $22k to CS grad students (and it's one of the strongest CS programs in the world), and $20k to math.

https://cs.illinois.edu/about/awards/graduate-fellowships-aw...

https://math.illinois.edu/admissions/graduate-admissions/fin...