Question: Which Soviet mathmatician won a Nobel Prize, Alexander Gelfond or Nikolay Bogolyubov?
Context: List of all published works of Nikolay Bogolyubov in chronological order (in preparation): Abdullah Sadiq, PhD, "SI" (born 1940), is a Pakistani physicist and ICTP laureate who received the ICTP Prize in the honour of Nikolay Bogolyubov, in the fields of Mathematics and Solid State Physics in 1987 for his contributions to scientific knowledge in the field of Mathematics and Statistical physics.  He is the professor of physics and current Dean of the Department of Physics of the Air University of the Pakistan Air Force (PAF). Alexander Osipovich Gelfond (Russian: Алекса́ндр О́сипович Ге́льфонд ; 24 October 1906 – 7 November 1968) was a Soviet mathematician.  Gelfond's theorem is named after him. The Krylov–Bogolyubov averaging method (Krylov–Bogolyubov method of averaging) is a mathematical method for approximate analysis of oscillating processes in non-linear mechanics.  The method is based on the averaging principle when the exact differential equation of the motion is replaced by its averaged version.  The method is named after Nikolay Krylov and Nikolay Bogoliubov. Bogoliubov causality condition is a causality condition for scattering matrix ("S"-matrix) in axiomatic quantum field theory.  The condition was introduced in axiomatic quantum field theory by Nikolay Bogolyubov in 1955. In theoretical physics, the Bogoliubov transformation, also known as Bogoliubov-Valatin transformation, were independently developed in 1958 by Nikolay Bogolyubov and John George Valatin for finding solutions of BCS theory in a homogeneous system.  The Bogoliubov transformation is an isomorphism of either the canonical commutation relation algebra or canonical anticommutation relation algebra.  This induces an autoequivalence on the respective representations.  The Bogoliubov transformation is often used to diagonalize Hamiltonians, which yields the stationary solutions of the corresponding Schrödinger equation.  The Bogoliubov transformation is also important for understanding the Unruh effect, Hawking radiation, pairing effects in nuclear physics, and many other topics. Unconventional superconductors are materials that display superconductivity which does not conform to either the conventional BCS theory or Nikolay Bogolyubov's theory or its extensions. Nikolay Nikolayevich Bogolyubov (Russian: Никола́й Никола́евич Боголю́бов ; 21 August 1909 – 13 February 1992), also transliterated as Bogoliubov and Bogolubov, was a Soviet mathematician and theoretical physicist known for a significant contribution to quantum field theory, classical and quantum statistical mechanics, and the theory of dynamical systems; He was the recipient of the 1992 Dirac Prize. In transcendental number theory, a mathematical discipline, Baker's theorem gives a lower bound for the absolute value of linear combinations of logarithms of algebraic numbers.  The result, proved by , subsumed many earlier results in transcendental number theory and solved a problem posed by Alexander Gelfond nearly fifteen years earlier. In mathematics, the Krylov–Bogolyubov theorem (also known as the existence of invariant measures theorem) may refer to either of the two related fundamental theorems within the theory of dynamical systems.  The theorems guarantee the existence of invariant measures for certain "nice" maps defined on "nice" spaces and were named after Russian-Ukrainian mathematicians and theoretical physicists Nikolay Krylov and Nikolay Bogolyubov who proved the theorems.
Answer: Alexander Osipovich Gelfond