George Adam Pfeiffer (16 July 1889, New York City[1] – 28 December 1943) was an American mathematician.
Pfeiffer received in 1910 his master's degree in engineering from Stevens Institute of Technology and then his A.M. in 1911 and in 1914 his Ph.D. in mathematics from Columbia University.
[5] Pfeiffer is known for publishing the first example of a holomorphic function with a non-linearizable irrational indifferent fixed point.
[7][8][9] The question of the linearizability of fixed points is of great importance in complex dynamics.
After Pfeiffer's example, Hubert Cremer gave various criteria for the non-linearizability of irrational indifferent fixed points, while Carl Ludwig Siegel in 1942 gave conditions which imply the linearizability of such fixed points.