Aleksandr Gelfond, also spelled as Alexander Gelfond, was born on October 24, 1906, in the town of Samara, Russia, He enrolled in Moscow State University, majoring in mathematics and completed his undergraduate studies in 1927. He then continued mathematical research under the guidance of the renowned Russian mathematicians Aleksandr Khinchin and Vyacheslaw Stepanov and completed his Ph.D. in 1930. During his doctoral studies he published several important papers including, The arithmetic properties of entire functions (1929); Transcendental numbers (1929); and An outline of the history and the present state of the theory of transcendental numbers (1930).
In 1934, Gelfond, along with Theodor Schneider, proved the Gelfond-Schneider theorem (sometimes referred to as Gelfond’s theorem). This theorem is a fundamental result in number theory and deals with the transcendence of certain types of numbers. It asserts that if a and b are algebraic numbers such that a is not equal to 0 or 1 and b is not equal to 0, then any value of ab is a transcendental number, provided that a is not equal to 1 and a is not a complex number with absolute value 1. This theorem has been influential in various mathematical developments, including the proof of the transcendence of π and e. A consequence of this theorem is the solution of Hilbert’s Seventh Problem.
Gelfond was elected as a Corresponding Member of the Academy of Sciences of the USSR for his work in the field of cryptography where he served the Soviet Navy as Chief Cryptographer during World War II. He passed away on November 7, 1968. The authors of his obituary wrote:
Gelfond devoted much time and effort to training of young scholars, with tact, kindness, and a sincere sensitivity, being remarkably individualistic himself, he valued and respected individuality in his pupils. Without restricting their views and tastes, he knew how to pass on to them his own devotion to science.
