In 1924 the first three absolute chairs of theoretical physics were assigned in Italy. The competition was won by Enrico Fermi, Aldo Pontremoli and Enrico Persico, who were appointed to the three chairs of some of the most prestigious Italian universities. This led Pontremoli himself to be assigned to the Lombard university, where he formed the so-called Institute of Complementary Physics, which he founded and directed, from 1924 to 1928, with the aim of founding a pole that would respond to the needs of science and technology, such as it suited the greatest Italian industrial center. Having had a part of the school building in via Sacchini available, he took care of the adaptation and the fixed installations so that the new Institute could carry out scientific and didactic activities effectively and without interference. With the means obtained by the university, he constituted the first nucleus of devices essential for the functioning of the new institution; through his relationships in the industrial field, he was able to complete these endowments with materials received as a gift. In this way the Institute in a short time was able to fully fulfill the task assigned to it. In November 1925 the institute was the organizer of the II Assembly of the International Federation of the Intellectual Union. Among the grants received by Pontremoli, the one received from Banca Popolare di Milano in 1926, which allowed the foundation of the radiology laboratory, specialized in ultraviolet radiation, and radioactive substances, should be noted. The foundation of the school, which later became part of the Physics Department of the University of Milan, was published in the physics magazine Il Nuovo Cimento, of the Italian Physics Society. Pontremoli's studies were particularly concerned with optics, radioactivity and hydrodynamics and were mainly published in the Rendiconti dei Lincei of the homonymous Academy and in the Reports of the Lombard Academy of Sciences and Letters. Some popular writings appeared in the magazine La Fiera Letteraria. In 1929, after the death of Aldo Pontremoli who died in the tragedy of the airship Italia who disappeared in the ice of Antarctica in May of the previous year, Giovanni Polvani replaced him in the chair of Experimental Physics of the Institute which became part of the University of Milan. The Polvani Archive, containing historical volumes, is still kept in the Physics Library of the University of Milan. A classroom in the university department was then named after him. In Milan, Polvani, already before the Second World War, is committed with Bolla and also with Gentile to find new tools to develop research on cosmic rays. Starting from 1936 the physical institute suffered a constant decline due to the conflicts between its protagonists and the fascist regime, many of which, following the fascist racial laws, left Italy to continue their research studies in the United States of America.