Her PhD activities, finished in 2012, were focused on the study of both philosophical and religious polemical texts produced in Spain in the thirteen and fourteen century, writings mostly produced in the Crown of Aragon. While doing research at the Neubauer Collegium as a visiting fellow (via the CASB Fellows Program) Celia delved into religious polemics between Jews and Christians in the end of the thirteen century, through the edition and analysis of the complete anti-Jews work by Ramon Llull (1232-1316), a key figure to the topic. She also aimed to establish definitive conclusions, based on textual proofs, on the real relationships between Llull and Judaism as well as with Jewish Philosophy.