Yohanan Ledermann was a Research Fellow at the Rosenzweig Center from January  2001 to June 2003 and from January 2005 to September 2005.

His topic during his first stay was titled "The Philosophy of the Enlightenment in Moses Mendelssohn's Biblical Exegesis". The topic of his post doctoral research was titled "Zyi Homberg's Ha-Korem as a Supercommentary of Mendelssohn's Biur".