When the slim percentage of Polish Jewry that survived the Holocaust returned home from the ghettos and concentration camps, they were not readily accepted back into the folds of Polish society. “They were physically present but socially absent,” Polish historian Lukasz Krzyzanowski tells The Times of Israel via Zoom call from his book-lined study in Warsaw. “Polish Jews after the war felt alone and socially isolated because there was no compassion or empathy forthcoming from their [non-Jewish] Polish compatriots.” In his book, “Ghost Citizens: Jewish Return to a Postwar City,” Kr...