_Hungarian_mathematician.jpg&w=384&q=75)
László Rédei
Who was László Rédei?
Hungarian mathematician
Biographical data adapted from Wikipedia’s article on László Rédei (CC BY-SA 4.0).
Biography
László Rédei (15 November 1900 – 21 November 1980) was a Hungarian mathematician who made significant contributions to algebraic number theory, group theory, and finite geometry, impacting twentieth-century mathematics. Born in Rákoskeresztúr, he pursued higher education at the University of Budapest, now known as Eötvös Loránd University, where he honed the algebraic skills that shaped his career. After graduating, he worked as a schoolteacher for a time, which was common for mathematically talented individuals in Hungary back then who were waiting for academic positions.
In 1940, Rédei became a professor at the University of Szeged, a leading hub for mathematical research in Hungary. He stayed there for nearly three decades, establishing himself as a prominent figure in Hungarian mathematics. In 1967, he joined the Mathematical Institute of the Hungarian Academy of Sciences in Budapest, where he continued his research until his death. He passed away in Budapest on 21 November 1980, shortly after his eightieth birthday.
Rédei's mathematical work was broad and deeply technical. He proved that every finite tournament has an odd number of Hamiltonian paths, a result well-known in combinatorics. He provided multiple independent proofs of the law of quadratic reciprocity and established key theorems about the invariants of class groups of quadratic number fields. He also studied when the ring of integers of a real quadratic field Q(√d) allows a Euclidean algorithm, solving several previously open cases. He expanded on Hajós's theorem about factoring abelian groups by subsets, which led him to study lacunary polynomials over finite fields. He summarized this research in his influential monograph "Lückenhafte Polynome über endlichen Körpern," which played a crucial role in finite geometry, particularly in the theory of blocking sets.
Beside these achievements, Rédei introduced a broad concept of the skew product of groups that brought together previously separate ideas, such as the Schreier extension and the Zappa–Szép product, into one cohesive framework. In 1947, he identified all finite noncommutative groups where every proper subgroup is commutative, a classification that foreshadowed the extensive project of classifying all finite simple groups. He was president of the János Bolyai Mathematical Society from 1947 to 1949 and became a corresponding member of the Hungarian Academy of Sciences in 1949, achieving full membership in 1955. He received several honors, including the Kőnig Gyula Award in 1940, the Kossuth Prize in 1950 and 1955, and the Szele Tibor commemorative medal in 1973. The Hungarian Heritage Award was given to him posthumously in 2007.
Before Fame
László Rédei was born in 1900 in Rákoskeresztúr, a settlement near Budapest that would later become part of the Hungarian capital. He grew up during a time of great change in Central Europe, including the break-up of the Austro-Hungarian Empire, the aftermath of World War I, and the political changes that followed. Despite these challenges, Hungary kept up a strong tradition of math education, and Rédei benefited from the rigorous curriculum at the University of Budapest.
After finishing his studies, Rédei worked as a schoolteacher. Many Hungarian mathematicians of his time followed this path before getting university positions. This phase didn't hinder his mathematical growth; it actually allowed him to develop his thoughts in algebra and number theory. His appointment to the University of Szeged in 1940, the same year he won the Kőnig Gyula Award, marked the start of his academic career and put him in a department that had historically attracted some of Hungary's best mathematical minds.
Key Achievements
- Proved that every finite tournament contains an odd number of Hamiltonian paths
- Generalized Hajós's theorem on factorization of abelian groups, leading to the theory of lacunary polynomials over finite fields
- Classified finite noncommutative groups in which all proper subgroups are commutative, an early result in the direction of the classification of finite simple groups
- Introduced a general skew product of groups unifying the Schreier extension and the Zappa–Szép product as special cases
- Published Lückenhafte Polynome über endlichen Körpern, a work that became foundational in finite geometry and blocking set theory
Did You Know?
- 01.Rédei produced several entirely independent proofs of the law of quadratic reciprocity, contributing to a long tradition of mathematicians who regarded new proofs of this classical theorem as worthwhile in their own right.
- 02.His 1947 classification of finite noncommutative groups whose proper subgroups are all commutative is now seen as an early step in the decades-long effort to classify all finite simple groups, a project completed only in the 1980s.
- 03.The book Lückenhafte Polynome über endlichen Körpern, which arose from his generalization of Hajós's theorem, became a foundational reference in finite geometry and the study of blocking sets, fields far removed from his original algebraic starting point.
- 04.Rédei received the Kossuth Prize twice, in 1950 and 1955, making him one of a select group of Hungarian scientists to be recognized at the highest national level on multiple occasions.
- 05.He served as president of the János Bolyai Mathematical Society from 1947 to 1949, a period that coincided with major political reorganization in Hungary following World War II.
Awards & Honors
| Award | Year | Details |
|---|---|---|
| Kossuth Prize | 1950 | — |
| Kossuth Prize | 1955 | — |
| Szele Tibor commemorative medal | 1973 | — |
| Hungarian Heritage Award | 2007 | — |
| Kőnig Gyula Award | 1940 | — |