The Chudnovsky brothers (both born in Kiev; David Volfovich in 1947; Gregory Volfovich in 1952) are American mathematicians known for their world-record mathematical calculations, their home-built supercomputers, and their close working relationship.
Careers in mathematics 
A 1992 article in The New Yorker quoted the opinion of several mathematicians that Gregory Chudnovsky is one of the world's best living mathematicians. David Chudnovsky works closely with and assists his brother Gregory, who has myasthenia gravis.
The Chudnovsky brothers have held records, at different times, for computing π to the largest number of places, including two billion digits in the early 1990s on a supercomputer they built (dubbed "m-zero") in their apartment in Manhattan. In 1987, the Chudnovsky brothers developed the algorithm (now called the Chudnovsky algorithm) that they used to break several π computation records. Today, this algorithm is used by Mathematica to calculate π, and has continued to be used by others who have achieved world records in pi calculation.
The brothers also assisted the Metropolitan Museum of Art around 2003 in the merging of a series of digital photographs taken of The Hunt of the Unicorn tapestries during their cleaning. PBS aired a program on its science show NOVA, hosted by Robert Krulwich, that described the difficulties in photographing the tapestries and the math used to fix them.