(Phys.org)—A pair of researchers, one with the Weizmann Institute of Science in Israel the other with Princeton University in the U.S. has come up with a possible explanation for the inability of space scientists to find any intermediate-sized black holes. In their paper published in the journal Nature Astronomy, Tal Alexander and Ben Bar-Or offer an outline of current theories regarding how black holes in general are believed to develop, theories about the early universe, and finally, their ideas on how current theories may lead to an explanation for the dearth of intermediate sized black holes.