Stefan Banach

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Stefan Banach
Stanislaw Ulam

Stefan Banach (Polish: [ˈstɛfan ˈbanax] ⓘ; 30 March 1892 – 31 August 1945) was a Polish mathematician[1] who is generally considered one of the 20th century's most important and influential mathematicians.[2] He was the founder of modern functional analysis,[1] and an original member of the Lwów School of Mathematics. His major work was the 1932 book, Théorie des opérations linéaires (Theory of Linear Operations), the first monograph on the general theory of functional analysis.[3]

Born in

Polish Academy of Learning in 1924. Banach was also a co-founder of the Lwów School of Mathematics, a school of thought comprising some of the most renowned Polish mathematicians of the interwar period
(1918–1939).

Some of the notable

Banach–Steinhaus theorem, the Banach–Mazur game, the Banach–Alaoglu theorem, and the Banach fixed-point theorem
.

Life

Early life

Stefan Banach was born on 30 March 1892 at St. Lazarus General Hospital in

Roman Catholic family,[4] and was subsequently baptised by his father.[5][6] Banach's parents were Stefan Greczek and Katarzyna Banach, both natives of the Podhale region.[7][8] Greczek was a soldier in the Austro-Hungarian Army stationed in Kraków. Little is known about Banach's mother.[5] According to his baptismal certificate, she was born in Borówna and worked as a domestic helper.[8]

Unusually, Stefan's surname was his mother's instead of his father's, though he received his father's given name, Stefan. Military regulations did not permit soldiers of Stefan Greczek's rank to marry; he was a private and as the mother was too poor to support the child, the couple decided that he should be reared by family and friends.[9] Stefan spent the first few years of his life with his grandmother, but when she was taken ill, Greczek arranged for his son to be raised by Franciszka Płowa and her niece Maria Puchalska in Kraków. Young Stefan came to regard Franciszka as his foster mother and Maria as his older sister.[10] In his early years Banach was tutored by Juliusz Mien, a French intellectual and friend of the Płowa family, who had emigrated to Poland and supported himself with photography and translations of Polish literature into French. Mien taught Banach French and most likely encouraged him in his early mathematical pursuits.[11]

In 1902, Banach, aged 10, enrolled in Kraków's IV Gymnasium (also known as the

Goetz Gymnasium). While the school specialized in the humanities, Banach and his best friend Witold Wiłkosz (also a future mathematician) spent most of their time working on mathematics problems during breaks and after school.[12] Later in life Banach credited Dr. Kamil Kraft, the mathematics and physics teacher at the school, with kindling his interests in mathematics.[13] While Banach was a diligent student he did, on occasion, receive low grades (he failed Greek during his first semester at the school) and later spoke critically of the school's math teachers.[14]

After obtaining his

Lwów Polytechnic. He initially chose engineering as his field of study since at the time he was convinced that there was nothing new to discover in mathematics.[15] At some point he also attended Jagiellonian University in Kraków on a part-time basis. As Banach had to earn money to support his studies it was not until 1914 that he finally, at age 22, passed his high school graduation exams.[16]

When

tutor at the local schools, worked in a bookstore and as a foreman of a road building crew. He attended some lectures at the Jagiellonian University at that time, including those of the famous Polish mathematicians Stanisław Zaremba and Kazimierz Żorawski, but little is known of that period of his life.[17]

Discovery by Steinhaus

Otto Nikodym and Stefan Banach Memorial Bench in Kraków, Poland
(sculpted by Stefan Dousa)

In 1916, in Kraków's

Otto Nikodym.[18] Steinhaus became fascinated with the self-taught young mathematician. The encounter resulted in a long-lasting collaboration and friendship. In fact, soon after the encounter Steinhaus invited Banach to solve some problems he had been working on but which had proven difficult. Banach solved them within a week and the two soon published their first joint work (On the Mean Convergence of Fourier Series). Steinhaus, Banach and Nikodym, along with several other Kraków mathematicians (Władysław Ślebodziński, Leon Chwistek, Alfred Rosenblatt[19] and Włodzimierz Stożek) also established a mathematical society, which eventually became the Polish Mathematical Society.[20]
The society was officially founded on 2 April 1919. It was also through Steinhaus that Banach met his future wife, Łucja Braus.

Interbellum

Scottish Café, meeting place of many famous Lwów mathematicians

Steinhaus introduced Banach to academic circles and substantially accelerated his career. After

University of Lwów
.

Young and talented, Banach gathered around him a large group of mathematicians. The group, meeting in the

Polish Academy of Sciences and Fine Arts
in Kraków.

World War II

Lwów, in Polish
)

After the

lice feeder at Professor Rudolf Weigl's Typhus Research Institute. Employment in Weigl's Institute provided many unemployed university professors and their associates protection from random arrest and deportation to Nazi concentration camps
.

After the Soviet

Lvov–Sandomierz Offensive of 1944, Banach returned to the university and helped re-establish it after the war years. However, because the Soviets were deporting Poles from annexed formerly Polish eastern territories, Banach began preparing to leave the city and settle in Kraków, Poland, where he had been promised a chair at the Jagiellonian University.[5] He was also considered a candidate for Minister of Education of Poland.[27] In January 1945, he was diagnosed with lung cancer and was permitted to stay in Lwów. He died on 31 August 1945, aged 53. His funeral at the Lychakiv Cemetery (Cmentarz Łyczakowski) was attended by hundreds of people.[27]

Contributions

Banach's dissertation, completed in 1920 and published in 1922, formally axiomatized the concept of a complete normed vector space and laid the foundations for the area of functional analysis. In this work Banach called such spaces "class E-spaces", but in his 1932 book, Théorie des opérations linéaires, he changed terminology and referred to them as "spaces of type B", which most likely contributed to the subsequent eponymous naming of these spaces after him.[28] The theory of what came to be known as Banach spaces had antecedents in the work of the Hungarian mathematician Frigyes Riesz (published in 1916) and contemporaneous contributions from Hans Hahn and Norbert Wiener.[21] For a brief period in fact, complete normed linear spaces were referred to as "Banach–Wiener" spaces in mathematical literature, based on terminology introduced by Wiener himself. However, because Wiener's work on the topic was limited, the established name became just Banach spaces.[28]

Likewise,

Banach–Schauder theorem) and other mathematicians (in particular Brouwer and Poincaré and Birkhoff). The theorem did not require linearity of the space, and applied to any complete Cauchy space (in particular to any complete metric space).[21]

Decomposition of a ball into two identical balls – the Banach–Tarski paradox

The Hahn–Banach theorem is one of the fundamental theorems of functional analysis.[21] Further theorems related to Banach are:

Recognition

In 1946, the

International Stefan Banach Prize has been conferred by the Polish Mathematical Society to mathematicians for best doctoral dissertations in the mathematical sciences with the objective to "promote and financially support the most promising young researchers".[30]

Stefan Banach is the patron of a number of schools and streets including in Warsaw, Lviv, Świdnica, Toruń and Jarosław.

In 2001, a minor planet

Paul Comba in 1997, was named after him.[31]

In 2012, the

zloty coin, silver 10-zloty coin and Nordic Gold 2-zloty coin).[32]

In 2016, a commemorative bench featuring Banach and

Otto Nikodym was unveiled in Kraków's Planty Park on the 100th anniversary of the conversation the two mathematicians held when they first met Hugo Steinhaus, which proved instrumental in the development of his scientific career.[33]

In 2021, one of the episodes of Polish documentary TV series Geniusze i marzyciele (Geniuses and Dreamers) aired on TVP1 and TVP Dokument channels was devoted to Stefan Banach.[34]

In 2022, Google Doodle commemorated the 100th anniversary of Banach receiving his title of professor.[35]

Quotes

Banach monument, Kraków

Stanislaw Ulam, another mathematician of the Lwów School of Mathematics
, in his autobiography, quotes Banach as saying:

"Good mathematicians see analogies between theorems or theories, the very best ones see analogies between analogies."[36]

Hugo Steinhaus said of Banach:

"Banach was my greatest scientific discovery."[37]

See also

References

Citations

  1. ^ a b "Stefan Banach - Polish Mathematician". britannica.com. 27 August 2023.
  2. ^ Pitici 2019, p. 23.
  3. ^ Chemla, Chorla & Rabouin 2016, pp. 224, 225, 237.
  4. ^ "Home Page of Stefan Banach". kielich.amu.edu.pl. Retrieved 19 August 2017.
  5. ^ a b c d O'Connor, John J.; Robertson, Edmund F., "Stefan Banach", MacTutor History of Mathematics Archive, University of St Andrews
  6. ^ Stachura 1999, p. 51.
  7. ^ Waksmundzka-Hajnos 2006, p. 16.
  8. ^ a b Duda 2009, p. 29.
  9. ^ Kałuża 1996, pp. 2–4
  10. ^ Kałuża 1996, pp. 1–3
  11. ^ Kałuża 1996, p. 3
  12. ^ Kałuża 1996, p. 137
  13. ^ Jakimowicz & Miranowicz 2007, p. 4
  14. ^ Kałuża 1996, pp. 3–4
  15. ^ Jakimowicz & Miranowicz 2007, p.5
  16. ^ Kałuża 1996, p. 13
  17. ^ Kałuża 1996, p. 16
  18. ^ Jakimowicz & Miranowicz 2007, p. 6
  19. ^ Ciesielska & Maligranda 2019, pp. 57–108.
  20. ^ Kałuża 1996, p. 23
  21. ^ a b c d Jahnke 2003, p. 402
  22. ^ Stefan Banach (1922). "Sur les opérations dans les ensembles abstraits et leur application aux équations integrals (On operations in the abstract sets and their application to integral equations)". Fundamenta Mathematicae (in French and Polish). 3.
  23. ^ "Математичний міст між Краковом і Львовом: як Стефан Банах став одним із найвеличніших математиків століття - krakow1.one". 16 November 2022.
  24. ^ Stefan Banach: Teoria operacji liniowych.
  25. ^ Stefan Banach: Théorie des opérations linéaires (in French; Theory of Linear Operations).
  26. ^ Urbanek 2002
  27. ^ a b James 2003, p. 384
  28. ^ a b MacCluer 2008, p. 6
  29. ^ Institute of Mathematics: Stefan Banach Medal Polish Academy of Sciences
  30. ^ "PIERWSZY LAUREAT "THE INTERNATIONAL BANACH PRIZE"" (in Polish). Archived from the original on 17 June 2015. Retrieved 11 August 2022.
  31. ISBN 978-83-244-0381-3
    .
  32. ^ "Narodowy Bank Polski. Monety" (PDF) (in Polish). Retrieved 11 August 2022.
  33. ^ "Setna rocznica najsłynniejszej matematycznej dyskusji na krakowskich Plantach" (in Polish). Archived from the original on 19 October 2016. Retrieved 11 August 2022.
  34. ^ ""Geniusze i marzyciele" – nowy serial dokumentalny w TVP1" (in Polish). Retrieved 11 August 2022.
  35. ^ "Stefan Banach: Google Doodle celebrates Polish mathematician". 22 July 2022. Retrieved 11 August 2022.
  36. ISBN 9780684143910
    .
  37. ^ Strick, Heinz Klaus (3 November 2016). "Stefan Banach (March 30, 1892 – August 8, 1945) – Mathematics in Europe". Mathematics in Europe. Translated by Kramer, David. European Mathematical Society. Retrieved 19 January 2024.{{cite web}}: CS1 maint: date and year (link)

Sources

Further reading

External links
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