Person: Sunyer, Ferran
Ferran Sunyer was a Catalan mathematician who overcame severe disabilities to produce some important results in complex analysis.
Mathematical Profile (Excerpt):
- Maria Carbona i Balaguer, Àngels Carbona i Balaguer and Ferran Carbona i Balaguer (1909-1979) were first cousins of Ferran Sunyer who were orphaned at a young age and brought up by Àngela Balaguer.
- This, we will see, is not irrelevant to a later positive episode in Ferran Sunyer's life.
- Ferran Sunyer was born with a severe motor disability which soon became apparent.
- There would have been no possibility of Ferran attending school.
- Sunyer had practically no use of his hands.
- That notebook full of formulas was the only tool Sunyer used in his work.
- Discovering an error on the book, Sunyer found a correct proof and, in early 1934, sent a short paper to Émile Picard who was the secretary of the Académie des Sciences in Paris.
- A covering letter explained that Sunyer hoped that the paper might be published but, if that was not possible, perhaps he might receive an opinion on it.
- Picard (who was 77 years old at this time) never replied to Sunyer and this might have dispirited anyone with less determination but, despite the difficulties he worked under, it did not prevent him from continuing to undertake research.
- In December 1938 Sunyer made another attempt to have a paper published.
- It was published in 1939 and in it Sunyer constructed a class of methods of analytic continuation.
- However, Sunyer's cousin, Ferran Carbona, had fled to Paris so that he could continue to support the Republican forces using his chemical knowledge to manufacture ammunition.
- He was able to get news to Sunyer regarding Hadamard's response in which he encouraged Sunyer to continue to undertake research.
- In the same year, 1939, Sunyer's first paper in Spanish was published, namely On a theorem of Professor Picard (Spanish), in which he proved the "little" Picard theorem by applying the theory of normal families in a new way.
- This paper was reviewed for Mathematical Reviews by Ralph Philip Boas Jr so, at this early stage, Boas became familiar with Sunyer's work.
- In 1942 Sunyer published On some results concerning the theorems of Picard, Landau and Schottky and on a criterion of quasinormality (Spanish).
- Sunyer lost contact with him at this time and it was only after Hadamard had spent a year in England and returned to Paris as soon as the war ended that he was able to resume contact sending him a memoir on lacunary Taylor series.
- This renewed contact, begun in 1946, was extremely important to Sunyer since Hadamard put him in contact with Szolem Mandelbrojt.
- He advised Sunyer on improvements to his mathematical style and also improvements to his French.
- Sunyer continued to publish papers such as On a class of transformations of the algorithms for summation of analytic series (Spanish) (1948), On the exclusion of an exceptional function by a gap condition (Spanish) (1948), Une généralisation des fonctions presque-périodiques Ⓣ(A generalization of the almost-periodic functions) (1949), A new generalization of almost periodic functions (Catalan) (1949), and Properties of entire functions (of finite order) represented by lacunary Taylor series (Spanish) (1949).
- Sunyer applied for a position in the CSIC in January 1948.
- Mandelbrojt was somewhat reluctant but, with Sunyer determined to talk to Sierpinski, the meeting took place.
- In any case it is remarkable that thanks to M Sunyer Balaguer, the error has been found 23 years after the appearance of the first edition of my book.
- Despite only being able to speak with great difficulty, Sunyer was able to lecture at conferences.
- Through Mandelbrojt, Sunyer had been put in contact with Archibald James Macintyre around 1956.
- In the following year Macintyre invited Sunyer to make a research visit to the United States in exchange for an American researcher visiting Barcelona.
- Sunyer was keen make the visit but, sadly, the University of Barcelona and CSIC both rejected his application.
- We mentioned above that Ralph Philip Boas Jr was familiar with Sunyer's work and it is worth recording that he was so taken with the 1954 result of Corominas and Sunyer quoted above that he wrote a whole book around it, namely A primer of real functions (1960).
- Despite his severe disability, Sunyer became more integrated into the mathematical community as the years went on and several mathematicians would visit him in his home in Barcelona.
- It was not until one month before his death that Sunyer was promoted to Scientific Researcher in CSIC.
- After his death, his cousins Maria Carbona i Balaguer and Àngels Carbona i Balaguer created the Foundation Ferran Sunyer i Balaguer in 1983.
- From 1993 The Ferran Sunyer i Balaguer Prize has been awarded for a mathematical monograph of an expository nature presenting the latest developments in an active area of research in Mathematics.
Born 6 February 1912, Figueres, Girona, Spain. Died 27 December 1967, Barcelona, Spain.
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Origin Spain
Thank you to the contributors under CC BY-SA 4.0! 
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- non-Github:
- @J-J-O'Connor
- @E-F-Robertson
References
Adapted from other CC BY-SA 4.0 Sources:
- O’Connor, John J; Robertson, Edmund F: MacTutor History of Mathematics Archive
