Padma Viswanathan’s Like Every Form of Love is hard to classify. The subtitle, “A Memoir of Friendship and True Crime,” comes close, but only scratches the surface of this complex and profound work. A novelist, translator, and teacher, Viswanathan divides her time between Montreal and Fayetteville, Arkansas, where she and her husband, poet Geoffrey Brock, both work as professors at the University of Arkansas.