Question: Who was sometimes known as Sasha Razborov, Boris Trakhtenbrot or Alexander Razborov?

Context paragraphs:
Sasha Krivtsov: Sasha Krivtsov, born (Alexander Krivtsov) June 6, 1967 in St. Petersburg, Russia, is probably best known as the bass player for the House Band on the TV reality shows , and The Voice.  He has played with singer-songwriter Vanessa Carlton.  He toured and recorded as bassist with Cher, Tina Turner, James Blunt, Shakira, Christina Aguilera, punk legend Billy Idol, Badly Drawn Boy and multi-platinum pop band The New Radicals.  Sasha and the House Band (Rafael Moreira (lead guitar), Paul Mirkovich (keyboards), Jim McGorman (rhythm guitar) and Nate Morton (drums)) toured the United States with Paul Stanley (from KISS) in October/November 2006 as well as Australia in April 2007.

Sascha Schmitz: Sascha Schmitz (born 5 January 1972), better known under his stage name Sasha or Sasha Alexander and his alter ego Dick Brave, is a German singer-songwriter, musician and occasional actor.

Alexander Razborov: Aleksandr Aleksandrovich Razborov (Russian: Алекса́ндр Алекса́ндрович Разбо́ров ; born February 16, 1963), sometimes known as Sasha Razborov, is a Soviet and Russian mathematician and computational theorist.

Trakhtenbrot's theorem: In logic, finite model theory, and computability theory, Trakhtenbrot's theorem (due to Boris Trakhtenbrot) states that the problem of validity in first-order logic on the class of all finite models is undecidable.  In fact, the class of valid sentences over finite models is not recursively enumerable (though it is co-recursively enumerable).

Steven Rudich: Steven Rudich (born October 4, 1961) is a professor in the Carnegie Mellon School of Computer Science.  In 1994, he and Alexander Razborov proved that a large class of combinatorial arguments, dubbed natural proofs were unlikely to answer many of the important problems in computational complexity theory.  For this work, they were awarded the Gödel prize in 2007.  He also co-authored a paper demonstrating that all currently known NP-complete problems remain NP-complete even under AC or NC reductions.

Sasha Song: Sasha Son (Russian: Dmitry Shavrov , Lithuanian: Dmitrijus Šavrovas , also known as Sasha Song, born 18 September 1983 in Vilnius, Lithuania) is a Lithuanian singer who represented Lithuania in the Eurovision Song Contest 2009.  His nickname Sasha Son means "Sasha Dream" in Russian, with Sasha being a Russian diminutive form of the name Alexander.

Color calibration: The aim of color calibration is to measure and/or adjust the color response of a device (input or output) to a known state.  In International Color Consortium (ICC) terms, this is the basis for an additional color characterization of the device and later profiling.  In non-ICC workflows, calibration refers sometimes to establishing a known relationship to a standard color space in one go.  The device that is to be calibrated is sometimes known as a "calibration source"; the color space that serves as a standard is sometimes known as a "calibration target".  Color calibration is a requirement for all devices taking an active part of a color-managed workflow.

Boris Trakhtenbrot: Boris (Boaz) Avraamovich Trakhtenbrot (Russian: Борис Авраамович Трахтенброт ; 19 February 1921 – 19 September 2016), or Boaz (Boris) Trakhtenbrot (Hebrew: בועז טרכטנברוט‎ ‎ ) was an Israeli and Russian mathematician in mathematical logic, algorithms, theory of computation, and cybernetics.  Trakhtenbrot was born in Brichevo, northern Bessarabia.  He worked at Akademgorodok, Novosibirsk during the 1960s and 1970s.

Sasha Krasny: Sasha Krasny (Russian: Саша Красный , literally "Alexander the Red") was the pen-name of Aleksandr Davydovich Bryansky (Russian: Александр Давыдович Брянский ; 28 September [O.S. 16 September] 1882 – 2 March 1995), a Russian poet and songwriter.  His first book was published in Odessa in 1912 and the last in 1993.  His son Boris Bryansky (1928–1972) was also a poet and songwriter.

Alexander romance: The Romance of Alexander is any of several collections of legends concerning the mythical exploits of Alexander the Great.  The earliest version is in the Greek language, dating to the 3rd century.  Several late manuscripts attribute the work to Alexander's court historian Callisthenes, but the historical person died before Alexander and could not have written a full account of his life.  The unknown author is still sometimes known as Pseudo-Callisthenes.

Supporting paragraphs: Boris Trakhtenbrot Alexander Razborov
Answer: Aleksandr Aleksandrovich Razborov