Alfréd Haar
Encyclopedia
Alfréd Haar was a Jewish Hungarian
mathematician
. In 1904 he began to study at the University of Göttingen. His doctorate was supervised by David Hilbert
. The Haar measure
, Haar wavelet
, and Haar transform are named in his honor.
Together with Frigyes Riesz
, he made the University of Szeged
a centre of mathematics. He also founded the Acta Scientiarum Mathematicarum
magazine together with Riesz.
, Hilbert
, Klein and Zermelo
.
During years of the secondary school, he collaborated with the mathematical journal for secondary school students Középiskolai Matematikai Lapok, and won the national Eötvös Loránd Mathematical Competition. He enrolled to the Technial University of Budapest as a student of Chemical Engineering, but in the same year he moved on to the University of Budapest, and after a year to the University of Göttingen. His doctoral research was supervised by Hilbert graduating in June 1909. His 49-page thesis studies systems of Sturm-Liouville functions and spherical functions, introducing the ever since wide-spreadly used Haar orthogonal systems. In the same year he habilitates to become a private professor of the university.
In 1902, the University of Kolozsvár (Cluj) invites him along with Farkas Gyula Riesz Frigyes to become a professor, and he becomes the professor of 'Quatitics'. A number of his lecture notes from the time became established books later. After the Treaty of Trianon
which ripped off vast areas of Hungary, the university had to move to Szeged, the closest city within the new boundaries, where he with Riesz established the Centre of Mathematics, and the first internationally recognised Hungarian mathematical journal, the Acta Scientiarum Mathematicarum.
He died of stomach cancer on 16 March 1933.
Hungary
Hungary , officially the Republic of Hungary , is a landlocked country in Central Europe. It is situated in the Carpathian Basin and is bordered by Slovakia to the north, Ukraine and Romania to the east, Serbia and Croatia to the south, Slovenia to the southwest and Austria to the west. The...
mathematician
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
. In 1904 he began to study at the University of Göttingen. His doctorate was supervised by David Hilbert
David Hilbert
David Hilbert was a German mathematician. He is recognized as one of the most influential and universal mathematicians of the 19th and early 20th centuries. Hilbert discovered and developed a broad range of fundamental ideas in many areas, including invariant theory and the axiomatization of...
. The Haar measure
Haar measure
In mathematical analysis, the Haar measure is a way to assign an "invariant volume" to subsets of locally compact topological groups and subsequently define an integral for functions on those groups....
, Haar wavelet
Haar wavelet
In mathematics, the Haar wavelet is a certain sequence of rescaled "square-shaped" functions which together form a wavelet family or basis. Wavelet analysis is similar to Fourier analysis in that it allows a target function over an interval to be represented in terms of an orthonormal function basis...
, and Haar transform are named in his honor.
Together with Frigyes Riesz
Frigyes Riesz
Frigyes Riesz was a mathematician who was born in Győr, Hungary and died in Budapest, Hungary. He was rector and professor at University of Szeged...
, he made the University of Szeged
University of Szeged
The University of Szeged is one of Hungary's most distinguished universities, and is among the most prominent higher education institutions in Central Europe...
a centre of mathematics. He also founded the Acta Scientiarum Mathematicarum
Acta Scientiarum Mathematicarum
Acta Scientiarum Mathematicarum is a Hungarian mathematical journal, edited and published in Szeged, at the János Bolyai Mathematical Institute of the University of Szeged. It was founded by Alfréd Haar and Frigyes Riesz in 1922. The current editor-in-chief is László Kérchy....
magazine together with Riesz.
Biography
He was born in Budapest on 11 October 1885 to Hungarian Jewish parents Ignác Haar and Emma Fuchs. He graduated in 1903 from the secondary school Fasori Evangélikus Gimnázium where he was a student of Rátz László. He started his university studies in Budapest, later moving on to Göttingen reading Mathematics and sciences. Among the many famous professors he was taught by, he could count Eötvös Loránd, Kürschák, CarathéodoryConstantin Carathéodory
Constantin Carathéodory was a Greek mathematician. He made significant contributions to the theory of functions of a real variable, the calculus of variations, and measure theory...
, Hilbert
David Hilbert
David Hilbert was a German mathematician. He is recognized as one of the most influential and universal mathematicians of the 19th and early 20th centuries. Hilbert discovered and developed a broad range of fundamental ideas in many areas, including invariant theory and the axiomatization of...
, Klein and Zermelo
Ernst Zermelo
Ernst Friedrich Ferdinand Zermelo was a German mathematician, whose work has major implications for the foundations of mathematics and hence on philosophy. He is known for his role in developing Zermelo–Fraenkel axiomatic set theory and his proof of the well-ordering theorem.-Life:He graduated...
.
During years of the secondary school, he collaborated with the mathematical journal for secondary school students Középiskolai Matematikai Lapok, and won the national Eötvös Loránd Mathematical Competition. He enrolled to the Technial University of Budapest as a student of Chemical Engineering, but in the same year he moved on to the University of Budapest, and after a year to the University of Göttingen. His doctoral research was supervised by Hilbert graduating in June 1909. His 49-page thesis studies systems of Sturm-Liouville functions and spherical functions, introducing the ever since wide-spreadly used Haar orthogonal systems. In the same year he habilitates to become a private professor of the university.
In 1902, the University of Kolozsvár (Cluj) invites him along with Farkas Gyula Riesz Frigyes to become a professor, and he becomes the professor of 'Quatitics'. A number of his lecture notes from the time became established books later. After the Treaty of Trianon
Treaty of Trianon
The Treaty of Trianon was the peace agreement signed in 1920, at the end of World War I, between the Allies of World War I and Hungary . The treaty greatly redefined and reduced Hungary's borders. From its borders before World War I, it lost 72% of its territory, which was reduced from to...
which ripped off vast areas of Hungary, the university had to move to Szeged, the closest city within the new boundaries, where he with Riesz established the Centre of Mathematics, and the first internationally recognised Hungarian mathematical journal, the Acta Scientiarum Mathematicarum.
He died of stomach cancer on 16 March 1933.
Fields of Research
His results are from the fields of mathematical analysis and topological groups, in particular he researched orthogonal systems of functions, singular integrals, analytic functions, partial differential equations, set theory, function approximation and calculus of variations.Publication
- Haar, A., Zur Theorie der orthogonalen Funktionensysteme, (Erste Mitteilung), Math. Ann. 69 (1910), 331-371 (at GDZ). (This is Haar's thesis, written under the supervision of David Hilbert.)
- Haar, A., Die Minkowskische Geometrie und die Annäherung an stetige Funktionen, Math. Ann. 78 (1918), 294-311 (at GDZ).