Collaboration and Friendship with Gianni

Both my wife and I have been bound by a deep friendship with Gianni, also involving his whole family. It is hard not to think with regret of the beautiful days spent together in Sardinia, of the walks on the Apuan Alps and in the Fauglia countryside, especially in the years when his sons Jacopo and Cecilia were children; all those are happy and poignant memories that are an important part of our lives. I met Gianni when he was an outstanding student of the course I was lecturing at the University of Pisa and then in 1971 as the supervisor of his thesis. The result was a scientific collaboration that continued until a few months before his death. I have no words to express my deep gratitude for what I have received from Gianni during our collaboration; his contributions and his role have always been crucial to achieving results. I still regret not having been able to get him the recognition from the scientific community and the right university position that he did deserve. In the course of my activity I have had the opportunity to meet illustrious and prestigious personalities in the field of theoretical and mathematical physics and Theoretical Physics, but I can affirm, without hesitation, that Gianni was no less, for his lucidity in grasping the core of the problems on the fly and solving them with the simplicity of essential logic, without resorting to gratuitous technicalities.