Question:
Which employer did Carlo Rovelli work for in Jan, 1989?

Context:
 Carlo Rovelli works for Yale University from Jan, 1987 to Jan, 1987. 
 Carlo Rovelli works for University of Pittsburgh from Jan, 1990 to Jan, 2000. 
 Carlo Rovelli works for Imperial College London from Jan, 1986 to Jan, 1986. 
 Carlo Rovelli works for Aix-Marseille University from Jan, 2012 to Dec, 2022. 
 Carlo Rovelli works for University of the Mediterranean - Aix Marseille II from Jan, 2000 to Jan, 2011. 
 Carlo Rovelli works for Syracuse University from Jan, 1989 to Jan, 1989. 
 Carlo Rovelli works for International School for Advanced Studies from Jan, 1989 to Jan, 1989. 
 Carlo Rovelli works for Sapienza University of Rome from Jan, 1987 to Jan, 1988.

Answer:
Syracuse University