Mat's areas of teaching and research include Global Catholicism (particularly Catholicism in India and Sri Lanka), Hinduism, and Modern Religious Movements. In addition to academic publications, Mat's work has appeared in Commonweal, U. S. Catholic, and The Best American Spiritual Writing series. Mat has served as a radio and television commentator on Catholicism for NPR, the BBC, ABC News, NECN, and CNBC. He also blogs regularly for the website On Faith.