Professor Vaidya, who spent his career at San Jose State University, was well-known for his work on the epistemology of modality, and for using contemporary analytic philosophy to explore and develop ideas from ancient Indian philosophy. There is a very nice memorial notice from the Society for Asian and Comparative Philosophy. He also wrote about his experience confronting a terminal illness here. Comments are open for remembrances from those who knew Professor Vaidya or for those who wish to comment on the significance of his work.
(Thanks to Malcolm Keating and Tim Williamson for the pointers.)