The Collatz-Wielandt formula, for positive matrices important in the Perron–Frobenius theorem, is named after him.
Liouville's theorem | Leo Frobenius | Chinese remainder theorem | Marshall Perron | Shannon–Hartley theorem | Quillen–Suslin theorem | Nyquist–Shannon sampling theorem | Hahn–Banach theorem | Frobenius | Fermat's Last Theorem | Buckingham π theorem | Thue–Siegel–Roth theorem | Szemerédi's theorem | Schottky's theorem | Riemann-Roch theorem | Pythagorean theorem | Nash embedding theorem | Müntz–Szász theorem | Malgrange–Ehrenpreis theorem | Kleene fixed-point theorem | Kakutani fixed-point theorem | Gauss–Bonnet theorem | Frobenius Orgelbyggeri | Doob's martingale convergence theorem | Dirichlet's theorem on arithmetic progressions | Denjoy theorem | Birch's theorem | Wilkie's theorem | Wick's theorem | Whitney extension theorem |
During the Battle of Ally Ghur, it was captured from the Marathas under the leadership of a French officer Perron by Lord Gerard Lake's British army, in September 1803, since which time it has been much strengthened and improved.
According to F. René Perron of Sèvres, Germain Doucet is from La Verdure, which is 10 kilometres north of Coutran, in the Bassevelle parish, which is in Champagne Brie.
With Aligarh Fort, it was also fortified and commanded by Perron till the Battle of Ally Ghur in the year of 1802, when it was laid under siege by the British 76th Regiment, now known as the Duke of Wellington's Regiment, under General Lord Gerard Lake.