Answer
Theoretical physics lies at the core of Abrikosov's work, encompassing diverse fields such as quantum mechanics, statistical physics, and condensed matter physics. His profound contributions advanced our comprehension of superconductivity, phase transitions, and the behavior of matter at extreme conditions. Through his theoretical explorations, Abrikosov unlocked the intricate relationships between the microscopic constituents and macroscopic properties of materials, shaping our understanding of the physical world.