George Adam Pfeiffer

George Adam Pfeiffer (born July 16, 1889 in New York - † December 28, 1943 ) was an American mathematician .

Pfeiffer received his master's degree from Stevens Institute of Technology in 1910 and his doctorate in 1914 from Columbia University . During World War I, he served in the US Army, teaching meteorology to students of aviation at Princeton University . After the war he taught at Columbia University. There he became an assistant professor in 1924 and an associate professor in 1931.

Today Pfeiffer is known for the first example of a holomorphic function with a non-linearizable irrationally indifferent fixed point. The question of the linearizability of fixed points is of great importance in complex dynamics . Cremer later specified various criteria for the non- linearizability of irrationally indifferent fixed points, while Siegel was able to specify conditions for the first time in 1942 from which linearizability follows.

Pfeiffer was co-editor of the Annals of Mathematics .

literature

Daniel Alexander, Felice Iavernaro, Alessandro Rosa: Early days in complex dynamics: a history of complex dynamics in one variable 1906-1940 , History of Mathematics 38, American Mathematical Society 2012; Pfeiffer's biography on p. 365

Individual evidence

↑ General Registry of the Members of the Phi Kappa Sigma Fraternity 1850-1920. Philadelphia, 1920; P. 448 online
^ GA Pfeiffer: Existence of divergent solutions of the functional equations , where is a given analytic function, in the irrational case. Bulletin of the American Mathematical Society, Vol. 22 (1916), p. 163; GA Pfeiffer: On the Conformal Mapping of Curvilinear Angles. The Functional Equation . Transactions of the American Mathematical Society, Volume 18 (1917), Issue 2, pp. 185-198; GA Pfeiffer: The functional equation . Annals of Mathematics (2nd episode), Volume 20 (1918), pp. 13-22. ${\ displaystyle \ varphi [g (x)] = a \ varphi (x), \ f [f (x)] = g (x)}$ ${\ displaystyle g (x)}$ ${\ displaystyle \ varphi [f (x)] = a_ {1} \ varphi (x)}$ ${\ displaystyle f [f (x)] = g (x)}$
↑ A presentation and discussion of the results by Pfeiffer, Cremer and Siegel can be found in the book by Alexander, Iavernaro and Rosa.

personal data
SURNAME	Pfeiffer, George Adam
BRIEF DESCRIPTION	American mathematician
DATE OF BIRTH	July 16, 1889
PLACE OF BIRTH	new York
DATE OF DEATH	December 28, 1943

[1] General Registry of the Members of the Phi Kappa Sigma Fraternity 1850-1920. Philadelphia, 1920; P. 448 online

[2] GA Pfeiffer: Existence of divergent solutions of the functional equations , where is a given analytic function, in the irrational case. Bulletin of the American Mathematical Society, Vol. 22 (1916), p. 163; GA Pfeiffer: On the Conformal Mapping of Curvilinear Angles. The Functional Equation . Transactions of the American Mathematical Society, Volume 18 (1917), Issue 2, pp. 185-198; GA Pfeiffer: The functional equation . Annals of Mathematics (2nd episode), Volume 20 (1918), pp. 13-22. ${\ displaystyle \ varphi [g (x)] = a \ varphi (x), \ f [f (x)] = g (x)}$ ${\ displaystyle g (x)}$ ${\ displaystyle \ varphi [f (x)] = a_ {1} \ varphi (x)}$ ${\ displaystyle f [f (x)] = g (x)}$

[3] A presentation and discussion of the results by Pfeiffer, Cremer and Siegel can be found in the book by Alexander, Iavernaro and Rosa.