Time travel is discussed from a variety of perspectives in "Time Machines: Time Travel in Physics, Metaphysics, and Science Fiction" by Paul J. Nahin, which is a wonderful book. Kip Thorne, a first-rate relativistist at Cal Tech, wrote a foreword for the second edition of this book. Here's a quote from his foreword: "It now is not only the most complete documentation of time travel in science fiction; it is also the most thorough review of serious scientific literature on the subject - a review that, remarkably, is scientifically accurate and at the same time largely accessible to a broad audience of nonspecialists."
See if your library has a copy of the second edition of this book; if not, get it through interlibrary loan. I think you'll find that this book has more than enough material for your paper.
Also, someone put the latest edition (Jan.? Feb. ?) of Astronomy Magazine on my desk today, and I noticed that the cover article is about time travel.
Regards,
George