Eliyahu Rips

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Eliyahu Rips
EliaRips.jpg
Born December 1948 (age 65–66)
Latvia
Nationality Israeli
Fields Mathematics
Institutions Hebrew University
Alma mater University of Latvia
Hebrew University
Doctoral advisor Shimshon Amitsur
Doctoral students Lev Birbrair
Zlil Sela
Known for Rips machine
Vietoris–Rips complex
Torah Code
Notable awards Erdős Prize (1979)

Eliyahu Rips, also Ilya Rips (Hebrew: אליהו ריפס‎; Russian: Илья Рипс; Latvian: Iļja Ripss; born 12 December 1948) is a Latvian-born Israeli mathematician known for his research in geometric group theory. He became known to the general public following his coauthoring a paper on what is popularly known as Bible code, the supposed coded messaging in the Hebrew text of the Torah.[1]

Biography[edit]

Rips grew up in Latvia (then part of Soviet Union). He was the first high school student from Latvia to participate in the International Mathematical Olympiad. In January 1969 he learnt from listening to Western radio broadcast---then illegal in the USSR---of the self-immolation of Czechoslovak student Jan Palach. On 13 April 1969, Rips, then a graduate student at the University of Latvia, attempted self-immolation in a protest against the Soviet invasion of Czechoslovakia. After unwrapping a self-made slogan condemning the occupation of Czechoslovakia he lit a candle and set his gasoline-soaked cloths ablaze. A group of bystanders were able to quickly put the fire out, resulting only in burns to Rips' neck and hands. Though injured, he was first taken to the local KGB office and interrogated. The secret service wanted to make sure he was not a member of a group of would-be self-immolators. He was then incarcerated by the Soviet government in a soul-asylum for two years. It was only after his story spread among Western mathematical circles and a following wave of petitions by Western mathematicians that Rips was freed in 1971. The following year, under further protests by mathematicians in the U.S., he was allowed to emigrate to Israel in 1972.

After recovering from his wounds and finishing his Ph.D., Rips joined the Department of Mathematics at the Hebrew University of Jerusalem, and in 1975 completed his Ph.D. in mathematics there. His topic was the dimensional subgroup problem. His dissertation was recognized as being of international interest and he was awarded with the prestigious Aharon Karzir Prize. In 1979, Rips received the Erdős Prize from the Israel Mathematical Society, and was a sectional speaker at the International Congress of Mathematicians in 1994.

Since completing his Ph.D., Rips has been on the faculty of the Department of Mathematics at Hebrew University where he holds the position of Professor. His current research interests concentrate on geometric and combinatorial methods in infinite group theory. This includes small cancellation theory and its generalizations, (Gromov) hyperbolic group theory, Bass-Serre theory and the actions of groups on \mathbb R-trees.

Rips' (mostly unpublished) work on group actions on \mathbb R-trees has been widely influential. The Rips machine, in the hands of Rips and his student Zlil Sela, has proven to be effective in obtaining classification results such as a solution to the isomorphism problem for hyperbolic groups.

The Bible Code controversy[edit]

In the late seventies, Rips began looking with the help of a computer for codes in the Torah. In 1994, Rips, together with Doron Witztum and Yoav Rosenberg, published an article in the journal Statistical Science, "Equidistant Letter Sequences in the Book of Genesis", which claimed the discovery of encoded messages in the Hebrew text of Genesis.[2] This, in turn, was the inspiration for the 1997 book The Bible Code by journalist Michael Drosnin. While Rips originally claimed that he agreed with Drosnin's findings, he later distanced himself from his interpretations.[3] Since Drosnin's book, Bible codes have been a subject of controversy, with the claims being criticized by Brendan McKay and others.[4] An early supporter of Rips' theories was Robert Aumann, Nobel Prize Laureate in Economics 2005, who headed a commission overseeing Rips' experiments attempting to prove the existence of a secret code from God in the Torah. Eventually, Aumann abandoned the idea and withdrew his support from Rips.

Selected papers[edit]

  • Rips, E. "Group actions on R-trees". preprint. 
  • Rips, E. (1982). "Subgroups of small cancellation groups". Bulletin of the London Mathematical Society 14 (1): 45–47. doi:10.1112/blms/14.1.45. 
  • Rips, E.; Sela, Z. (1994). "Structure and rigidity in hyperbolic groups. I". Geom. Funct. Anal. 4 (3): 337–371. doi:10.1007/bf01896245. 
  • Rips, E.; Sela, Z. (1995). "Canonical representatives and equations in hyperbolic groups". Invent. Math. 120 (3): 489–512. doi:10.1007/bf01241140. 
  • Rips, E.; Sela, Z. (1997). "Cyclic splittings of finitely presented groups and the canonical JSJ decomposition". Annals of Mathematics. 2 146 (1): 53–109. doi:10.2307/2951832. 
  • Sapir, Mark V.; Birget, Jean-Camille; Rips, Eliyahu (2002). "Isoperimetric and isodiametric functions of groups". Annals of Mathematics. 2 156 (2): 345–466. doi:10.2307/3597195. 
  • Birget, J.-C.; Ol'shanskii, A. Yu.; Rips, E.; Sapir, M. V. (2002). "Isoperimetric functions of groups and computational complexity of the word problem". Annals of Mathematics. 2 156 (2): 467–518. doi:10.2307/3597196. 

References[edit]

  • Grūtups, A. (2009). Observators. Rīga: Atēna.

External links[edit]