250px Francesco Gerbaldi (29 July 1858, La Spezia,

Kingdom of Sardinia The Kingdom of Sardinia, also referred to as the Kingdom of Sardinia and Corsica among other names, was a State (polity), country in Southern Europe from the late 13th until the mid-19th century, and from 1297 to 1768 for the Corsican part of ...

– 29 June 1934, Pavia, Italy) was an Italian geometer, who proved Gerbaldi's theorem. Gerbaldi studied at the

University of Turin The University of Turin (Italian language, Italian: ''Università degli Studi di Torino'', UNITO) is a public university, public research university in the city of Turin, in the Piedmont (Italy), Piedmont region of Italy. It is one of the List ...

with ''laurea'' in 1879 and then became there an assistant to

Enrico D'Ovidio Enrico D'Ovidio (1842–1933) was an Italian mathematician who is known by his works on geometry. Life and work D'Ovidio, son of liberal parents involved in the Italian independence movement, studied at the University of Naples under his uncl ...

. After further study in Germany, he was in Pavia and Rome before being appointed a professor at the

University of Palermo The University of Palermo () is a public university, public research university in Palermo, Italy. It was founded in 1806, and is currently organized in 12 Faculties. History The University of Palermo was officially founded in 1806, although it ...

. He was a colleague of Giovanni Guccia, the founder of the Circolo Matematico di Palermo. Guccia and Gerbaldi enhanced the reputation of the Faculty of Mathematics of the University of Palermo by recruiting Giuseppe Bagnera, Michele De Franchis, Pasquale Calapso and

Michele Cipolla Michele Cipolla (28 October 1880, Palermo – 7 September 1947, Palermo) was an Italian mathematician, mainly specializing in number theory. He was a professor of Algebraic Analysis at the University of Catania and, later, the University of P ...

. In 1908 Gerbaldi moved to the

University of Pavia The University of Pavia (, UNIPV or ''Università di Pavia''; ) is a university located in Pavia, Lombardy, Italy. There was evidence of teaching as early as 1361, making it one of the List of oldest universities in continuous operation, oldest un ...

, where he remained until his retirement in 1931 due to ill health. He is known for what is now called Gerbaldi's theorem, the construction of six pairwise apolar linearly independent nondegenerate ternary quadratic forms (the lowest dimensional

quadric In mathematics, a quadric or quadric surface is a generalization of conic sections (ellipses, parabolas, and hyperbolas). In three-dimensional space, quadrics include ellipsoids, paraboloids, and hyperboloids. More generally, a quadric hype ...

s). Later he studied the symmetry group of these six quadrics and found that it is isomorphic to the

Valentiner group In mathematics, the Valentiner group is the perfect triple cover of the alternating group on 6 points, and is a group of order 1080. It was found by in the form of an action of ''A''6 on the complex projective plane, and was studied further by . ...

. In 1897 in Zürich, Gerbaldi was an Invited Speaker at the first

International Congress of Mathematicians The International Congress of Mathematicians (ICM) is the largest conference for the topic of mathematics. It meets once every four years, hosted by the International Mathematical Union (IMU). The Fields Medals, the IMU Abacus Medal (known before ...

References

* 19th-century Italian mathematicians 20th-century Italian mathematicians 1858 births 1934 deaths {{Italy-mathematician-stub