It's called The Philosophy of Time Travel.
5 seconds sound clip from the Donnie Darko movie soundboard.
You can hear this line at 00:53:32 in the Blu-ray version of the movie.
Quote context
[...]
- Listen, um, don't tell anybody that I gave you this. The woman who wrote this used to teach here.
- The Philosophy of Time Travel. Roberta Sparrow?
- Roberta Sparrow. Grandma Death.
- It's called The Philosophy of Time Travel.
- What does philosophy have to do with time travel?
- Who? Roberta Sparrow? Huh. She wrote a book.
- We almost hit her with the car the other day.
[...]