Jewish Military Union
In 1957, Arens became professor of aeronautics at the Technion, serving in this position until 1962. After retiring from the government, he devoted himself to researching and commemorating the story of the Jewish Military Union (ŻZW), which fought alongside the better known Jewish Combat Organization (ŻOB) in the Warsaw Ghetto Uprising. Arens is the author of a number of articles on the revolt as well as a book, "Flags over the Warsaw Ghetto", which has been published in Hebrew, Polish and English.