Excerpt:
“Among these papers by Galileo, on page 31 recto, there is a list of “places where [Lodovico Delle Colombe] speaks of me with contempt.” Dr Cosci noticed that those “places” are precise references to some selected textual passages in Lodovico Delle Colombe’s Risposte. Then he realised that those passages do not openly attack Galileo (who is never even mentioned), but do attack Alimberto Mauri. The fact that Galileo felt personally “attacked” whenever Alimberto Mauri was attacked in print confirms that Alimberto Mauri was his alter ego. Simply put, in these private notes, Galilei himself reveals his identity as the one hiding behind a pseudonym.”
See also (in German): https://www.derstandard.at/story/2000139774395/forscher-enthuellt-pseudonym-des-galileo-galilei