Pyotr Yakovlevich Ufimtsev (Russian: ???? ?´???????? ???´????) (born 1931 in Ust-Charyshskaya Pristan, West Siberian Krai, now Altai Krai) is a Soviet/Russian physicist and mathematician, considered the seminal force behind modern stealth aircraft technology.
In the 1960s he began developing equations for predicting the reflection of electromagnetic waves from simple two-dimensional and three-dimensional objects.Much of Ufimtsev's work was translated into English, and in the 1970s American Lockheed engineers began to expand upon some of his theories to create the concept of aircraft with reduced radar signatures.