Aron Aji, a literary translator and professor at the University of Iowa, runs a Facebook group called Literary Translation with more than 4,300 members from 99 countries. For the most part, the group is an active, amiable one in which linguaphiles help one another with translator minutia. But events last month sent the Facebook group — and the little-known, underappreciated world of literary translation — into commotion, resulting in heated exchanges about issues of race and equity in the business.