mathematics

László Rédei

László Rédei is a mathematics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand László Rédei rather than just read about it. In short: László Rédei (15 November 1900 – 21 November 1980) was a Hungarian mathematician. Rédei graduated from the University of Budapest and initially worked as a schoolteacher.

Key takeaways

László Rédei belongs to mathematics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect László Rédei to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of László Rédei from memory before moving on to harder problems.

Reference excerpt

László Rédei (15 November 1900 – 21 November 1980) was a Hungarian mathematician. Rédei graduated from the University of Budapest and initially worked as a schoolteacher. In 1940 he was appointed professor in the University of Szeged and in 1967 moved to the Mathematical Institute of the Hungarian Academy of Sciences in Budapest. His mathematical work was in algebraic number theory and abstract algebra, especially group theory. He proved that every finite tournament contains an odd number of Hamiltonian paths. He gave several proofs of the theorem on quadratic reciprocity. He proved important results concerning the invariants of the class groups of quadratic number fields. In several cases, he determined if the ring of integers of the real quadratic field Q(√d) is Euclidean or not. He successfully generalized Hajós's theorem. This led him to the investigations of lacunary polynomials over finite fields, which he eventually published in a book. This work on lacunary polynomials has had a big influence in the field of finite geometry where it plays an important role in the theory of blocking sets. He introduced a very general notion of skew product of groups, of which both the Schreier-extension and the Zappa–Szép product are special case. He explicitly determined those finite noncommutative groups whose all proper subgroups were commutative (1947). This is one of the very early results which eventually led to the classification of all finite simple groups. Rédei was the president of the János Bolyai Mathematical Society (1947–1949). He was awarded the Kossuth Prize twice. He was elected corresponding member (1949), full member (1955) of the Hungarian Academy of Sciences.

Books 1959: Algebra. Erster Teil, Mathematik und ihre Anwendungen in Physik und Technik, Reihe A, 26, Teil 1 Akademische Verlagsgesellschaft, Geest & Portig, K.-G., Leipzig, xv+797 pp. 1967: English translation, Algebra, volume 1, Pergamon Press 1963: Theorie der endlich erzeugbaren kommutativen Halbgruppen, Hamburger Mathematische Einzelschriften, 41, Physica-Verlag, Würzburg 228 pp. 1968: Foundation of Euclidean and non-Euclidean geometries according to F. Klein, Pergamon Press, 404 pp. 1970: Lückenhafte Polynome über endlichen Körpern, Lehrbücher und Monographien aus dem Gebiete der exakten Wissenschaften, Mathematische Reihe, 42, Birkhäuser Verlag, Basel-Stuttgart, 271 pp. 1973: English translation: I. Földes: Lacunary Polynomials over Finite Fields North--Holland, London and Amsterdam, American Elsevier, New York, ISBN 0-7204-2050-4 (Europe) ISBN 0-444-10400-3 (US) 1989: Endliche p-Gruppen, Akadémiai Kiadó, Budapest, 304 pp. ISBN 963-05-4660-4

References

1981: László Rédei, Acta Scientiarum Mathematicarum, 43: 1–2 L. Márki (1985) "A tribute to L. Rédei", Semigroup Forum, 32, 1–21.

External links O'Connor, John J.; Robertson, Edmund F., "László Rédei", MacTutor History of Mathematics Archive, University of St Andrews László Rédei at the Mathematics Genealogy Project

Illustrations

Worked examples

Example 1 — a first encounter with László Rédei

Start with the simplest possible case. Write down what László Rédei claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In mathematics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to László Rédei before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about László Rédei ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of László Rédei

In research: László Rédei appears in mathematics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses László Rédei in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: László Rédei is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1900 births, 1980 deaths, 20th-century Hungarian mathematicians, so understanding it makes those chapters shorter.
In everyday life: Look for László Rédei outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study László Rédei in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what László Rédei means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain László Rédei out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is László Rédei in simple terms?

László Rédei (15 November 1900 – 21 November 1980) was a Hungarian mathematician. Rédei graduated from the University of Budapest and initially worked as a schoolteacher.

Why does László Rédei matter?

Because it connects several mathematics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study László Rédei?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on László Rédei.