Piven and her husband taught at Columbia (Economics>). Obama supposedly attended studying Poli Sci. I believe he actually studied with Cloward/Piven learning about their theory on how to transform the US into a Socialist country. That is the reason no Poli Sci. students remember Obama.
Years later both Obama and Piven were on the dais together teaching Alinsky’s “Rules for Radical’s.” Prof.s Cloward and Piven were also frequent guests at the Clinton White House.
Piven taught some courses at the Columbia School of Social Work but that was ten years before Obama went to Columbia College and Piven wasn’t teaching there then.
When Obama was at Columbia, Piven was a professor at Boston University. She had a very strained relationship with the president there and he would never have allowed her to have a joint appointment at another university. She later moved to CUNY, not Columbia.
Obama couldn’t have been one of her students although she might have been invited to give guest lectures in some of Cloward’s classes.