Gennady V. Chibisov (1946-2008) was a Soviet and Russian theoretical physicist and cosmologist, primarily known for his pioneering work with Viatcheslav Mukhanov on the origin of cosmic structures, developed in the early 1980s. Their theory demonstrated for the first time how quantum fluctuations during primordial cosmic inflation could be amplified by gravity, generating the density inhomogeneities that later gave rise to galaxies and galaxy clusters. This fundamental result, described in their 1981 paper, provided the theoretical basis for the anisotropies observed in the cosmic microwave background radiation. During his career, Chibisov worked at the Lebedev Physical Institute in Moscow. For this contribution, he and Mukhanov received the Gold Medal of the USSR Academy of Sciences in 1988. His role was also posthumously recognized through numerous other prestigious international awards for their joint discovery, solidifying his legacy as a key figure in modern cosmology.