Aleksander Rajchman
   HOME

TheInfoList



OR:

Aleksander Michał Rajchman (13 November 1890 in
Warsaw Warsaw ( pl, Warszawa, ), officially the Capital City of Warsaw,, abbreviation: ''m.st. Warszawa'' is the capital and largest city of Poland. The metropolis stands on the River Vistula in east-central Poland, and its population is officia ...
,
Poland Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populou ...
– July or August 1940 in
Sachsenhausen concentration camp Sachsenhausen () or Sachsenhausen-Oranienburg was a German Nazi concentration camp in Oranienburg, Germany, used from 1936 until April 1945, shortly before the defeat of Nazi Germany in May later that year. It mainly held political prisoner ...
,
Oranienburg Oranienburg () is a town in Brandenburg, Germany. It is the capital of the district of Oberhavel. Geography Oranienburg is a town located on the banks of the Havel river, 35 km north of the centre of Berlin. Division of the town Oranienburg ...
,
Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
) was a mathematician of the
Warsaw School of Mathematics Warsaw School of Mathematics is the name given to a group of mathematicians who worked at Warsaw, Poland, in the two decades between the World Wars, especially in the fields of logic, set theory, point-set topology and real analysis. They pu ...
of the Interwar period. He had origins in the
Lwów School of Mathematics The Lwów school of mathematics ( pl, lwowska szkoła matematyczna) was a group of Polish mathematicians who worked in the interwar period in Lwów, Poland (since 1945 Lviv, Ukraine). The mathematicians often met at the famous Scottish Café to ...
and contributed to
real analysis In mathematics, the branch of real analysis studies the behavior of real numbers, sequences and series of real numbers, and real functions. Some particular properties of real-valued sequences and functions that real analysis studies include conv ...
,
probability Probability is the branch of mathematics concerning numerical descriptions of how likely an event is to occur, or how likely it is that a proposition is true. The probability of an event is a number between 0 and 1, where, roughly speakin ...
and
mathematical statistics Mathematical statistics is the application of probability theory, a branch of mathematics, to statistics, as opposed to techniques for collecting statistical data. Specific mathematical techniques which are used for this include mathematical an ...
.


Family Background

Rajchman was born in Congress Poland, a province of the
Russian Empire The Russian Empire was an empire and the final period of the Russian monarchy from 1721 to 1917, ruling across large parts of Eurasia. It succeeded the Tsardom of Russia following the Treaty of Nystad, which ended the Great Northern War. ...
, in the family of assimilated
Polish Jews The history of the Jews in Poland dates back at least 1,000 years. For centuries, Poland was home to the largest and most significant Ashkenazi Jewish community in the world. Poland was a principal center of Jewish culture, because of the l ...
known for contributions to the 20th-century Polish intellectual life. Although the family was partially converted into Roman Catholicism, his parents were agnostic. His father Aleksander Rajchman was a journalist specialized in theatre and music critique, who in the period 1882-1904 was the publisher and editor-in-chief of the artistic weekly ''Echo Muzyczne, Teatralne i Artystyczne'' and was co-founder and first director of the
National Philharmonic in Warsaw The National Philharmonic in Warsaw ( Polish: ''Filharmonia Narodowa w Warszawie'') is a Polish cultural institution, located at 5 Jasna Street in Warsaw. The building was built between 1900 and 1901, under the direction of Karol Kozłowski, ...
in the years 1901–1904. Mother Melania Amelia Hirszfeld was a socialist and women's rights activist who wrote both critical essays and woman affairs' texts under pseudonyms or anonymously for a few Polish weeklies, organized maternal rallies where she drew attention to the need to improve the household to facilitate women's lives, and was an active member of the secret organization Women's Circle of Polish Crown and Lithuania, and later also the Association of Women's Equality in Warsaw. Rajchmans ran a social salon who hosted many Polish artists of their times, in particular
Eliza Orzeszkowa Eliza Orzeszkowa (6 June 184118 May 1910) was a Polish novelist and a leading writerEliza Orzeszkowa< ...
, Maria Konopnicka, and Zenon Pietkiewicz. His older sister a Polish independence activist and historian of education Helena Radlińska was the founder of Polish social pedagogy, his older brother a physician and bacteriologist Ludwik Rajchman was the world leader in
social medicine The field of social medicine seeks to implement social care through # understanding how social and economic conditions impact health, disease and the practice of medicine and # fostering conditions in which this understanding can lead to a health ...
and director of the
League of Nations The League of Nations (french: link=no, Société des Nations ) was the first worldwide intergovernmental organisation whose principal mission was to maintain world peace. It was founded on 10 January 1920 by the Paris Peace Conference that ...
Health Organization Health, according to the World Health Organization, is "a state of complete physical, mental and social well-being and not merely the absence of disease and infirmity".World Health Organization. (2006)''Constitution of the World Health Organiza ...
, the founder of the United Nations International Children's Emergency Fund (UNICEF) and its first Chairman in the years 1946–1950. His nephew a Polish-American electrical engineer Jan A. Rajchman was a computer pioneer who invented logic circuits for arithmetic and
magnetic-core memory Magnetic-core memory was the predominant form of random-access computer memory for 20 years between about 1955 and 1975. Such memory is often just called core memory, or, informally, core. Core memory uses toroids (rings) of a hard magneti ...
to result in development of high-speed computer memory systems and whose son John Rajchman is a noted American philosopher of art history, architecture, and continental philosophy. His first cousin a microbiologist and serologist
Ludwik Hirszfeld Ludwik Hirszfeld (5 August 1884 – 7 March 1954) was a Polish microbiologist and serologist. He is considered a co-discoverer of the inheritance of ABO blood types. Life He was a cousin of Aleksander Rajchman, a Polish mathematician, and of ...
co-discovered the heritability of ABO blood group type and foreseen the serological conflict between mother and child.


Education and Research Work

After his father died in 1904, his mother migrated with rest of the family to Paris in 1909. Alexander studied there and obtained the licencié és sciences degree in 1910. He became a junior assistant at the
University of Warsaw The University of Warsaw ( pl, Uniwersytet Warszawski, la, Universitas Varsoviensis) is a public university in Warsaw, Poland. Established in 1816, it is the largest institution of higher learning in the country offering 37 different fields o ...
in 1919, whereas in 1921 he earned the doctoral degree at the John Casimir
University of Lwów The University of Lviv ( uk, Львівський університет, Lvivskyi universytet; pl, Uniwersytet Lwowski; german: Universität Lemberg, briefly known as the ''Theresianum'' in the early 19th century), presently the Ivan Franko Na ...
under Hugo Steinhaus and became a senior assistant at the University of Warsaw. Next in 1922 he became a professor at the University of Warsaw, and, after his habilitation in 1925, a lecturer there until outbreak of the
World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
in 1939. In the 1930s, he was a
visiting scholar In academia, a visiting scholar, visiting researcher, visiting fellow, visiting lecturer, or visiting professor is a scholar from an institution who visits a host university to teach, lecture, or perform research on a topic for which the visitor ...
to lecture at the
Jacques Hadamard Jacques Salomon Hadamard (; 8 December 1865 – 17 October 1963) was a French mathematician who made major contributions in number theory, complex analysis, differential geometry and partial differential equations. Biography The son of a teac ...
's seminar at the
Collège de France The Collège de France (), formerly known as the ''Collège Royal'' or as the ''Collège impérial'' founded in 1530 by François I, is a higher education and research establishment ('' grand établissement'') in France. It is located in Paris n ...
. His research touched real analysis, probability and mathematical statistics, in particular focused on the Fourier series. Rajchman received significant results in the fields of
trigonometric series In mathematics, a trigonometric series is a infinite series of the form : \frac+\displaystyle\sum_^(A_ \cos + B_ \sin), an infinite version of a trigonometric polynomial. It is called the Fourier series of the integrable function f if the term ...
,
function of a real variable In mathematical analysis, and applications in geometry, applied mathematics, engineering, and natural sciences, a function of a real variable is a function whose domain is the real numbers \mathbb, or a subset of \mathbb that contains an interv ...
and
probability Probability is the branch of mathematics concerning numerical descriptions of how likely an event is to occur, or how likely it is that a proposition is true. The probability of an event is a number between 0 and 1, where, roughly speakin ...
. In mathematics, there are such concepts as the Rajchman global uniqueness theorem, Rajchman measures, Rajchman collection, Rajchman algebras, Rajchman sharpened law of large numbers, Rajchman theory of formal multiplication of trigonometric series, Rajchman inequalities, and Rajchman-Zygmund inequalities. Near a Rajchman measure, particularly important notion invented by Rajchman is a Rajchman algebra associated with a
locally compact group In mathematics, a locally compact group is a topological group ''G'' for which the underlying topology is locally compact and Hausdorff. Locally compact groups are important because many examples of groups that arise throughout mathematics are loc ...
which is defined to be the set of all elements of the Fourier-Stieltjes algebra which vanish at infinity, a closed and complemented ideal in the Fourier-Stieltjes algebra that contains the Fourier algebra. His first doctoral student a noted Polish mathematician
Antoni Zygmund Antoni Zygmund (December 25, 1900 – May 30, 1992) was a Polish mathematician. He worked mostly in the area of mathematical analysis, including especially harmonic analysis, and he is considered one of the greatest analysts of the 20th century. ...
created the Chicago school of mathematical analysis with the emphasis onto harmonic analysis, which produced the 1966 Fields Medal winner
Paul Cohen Paul Joseph Cohen (April 2, 1934 – March 23, 2007) was an American mathematician. He is best known for his proofs that the continuum hypothesis and the axiom of choice are independent from Zermelo–Fraenkel set theory, for which he was award ...
. His second doctoral student
Zygmunt Zalcwasser Zygmunt Zalcwasser (1898 – 1943) was a Polish mathematician from the Warsaw School of Mathematics in the period between the World Wars collaborating especially in the fields of logic, set theory, general topology and real analysis. Zalcwasser, w ...
, co-advised by
Wacław Sierpiński Wacław Franciszek Sierpiński (; 14 March 1882 – 21 October 1969) was a Polish mathematician. He was known for contributions to set theory (research on the axiom of choice and the continuum hypothesis), number theory, theory of functions, and t ...
, introduced the Zalcwasser rank to measure the
uniform convergence In the mathematical field of analysis, uniform convergence is a mode of convergence of functions stronger than pointwise convergence. A sequence of functions (f_n) converges uniformly to a limiting function f on a set E if, given any arbitrarily ...
of
sequences In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed and order matters. Like a set, it contains members (also called ''elements'', or ''terms''). The number of elements (possibly infinite) is called t ...
of
continuous functions In mathematics, a continuous function is a function such that a continuous variation (that is a change without jump) of the argument induces a continuous variation of the value of the function. This means that there are no abrupt changes in valu ...
on the
unit interval In mathematics, the unit interval is the closed interval , that is, the set of all real numbers that are greater than or equal to 0 and less than or equal to 1. It is often denoted ' (capital letter ). In addition to its role in real analysis ...
. In October 2000, the
Stefan Banach Stefan Banach ( ; 30 March 1892 – 31 August 1945) was a Polish mathematician who is generally considered one of the 20th century's most important and influential mathematicians. He was the founder of modern functional analysis, and an origina ...
International Mathematical Center at the Institute of Mathematics of the
Polish Academy of Sciences The Polish Academy of Sciences ( pl, Polska Akademia Nauk, PAN) is a Polish state-sponsored institution of higher learning. Headquartered in Warsaw, it is responsible for spearheading the development of science across the country by a society o ...
honoured Rajchman's achievements by the Rajchman-Zygmund- Marcinkiewicz Symposium. In April 1940
Gestapo The (), abbreviated Gestapo (; ), was the official secret police of Nazi Germany and in German-occupied Europe. The force was created by Hermann Göring in 1933 by combining the various political police agencies of Prussia into one orga ...
arrested Rajchman as a
Jew Jews ( he, יְהוּדִים, , ) or Jewish people are an ethnoreligious group and nation originating from the Israelites Israelite origins and kingdom: "The first act in the long drama of Jewish history is the age of the Israelites""T ...
, he died in
Oranienburg Oranienburg () is a town in Brandenburg, Germany. It is the capital of the district of Oberhavel. Geography Oranienburg is a town located on the banks of the Havel river, 35 km north of the centre of Berlin. Division of the town Oranienburg ...
,
Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
imprisoned by the
Nazis Nazism ( ; german: Nazismus), the common name in English for National Socialism (german: Nationalsozialismus, ), is the far-right totalitarian political ideology and practices associated with Adolf Hitler and the Nazi Party (NSDAP) in N ...
in the
Sachsenhausen concentration camp Sachsenhausen () or Sachsenhausen-Oranienburg was a German Nazi concentration camp in Oranienburg, Germany, used from 1936 until April 1945, shortly before the defeat of Nazi Germany in May later that year. It mainly held political prisoner ...
probably in July or August 1940.


See also

*
List of Polish mathematicians A list of notable Polish mathematicians: References {{Reflist Mathematicians A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concern ...


References

*
Aleksander Rajchman
from an article by Antoni Zygmund * * Polish mathematicians Scientists from Warsaw People from Warsaw Governorate People who died in Sachsenhausen concentration camp Polish Jews who died in the Holocaust 1890 births 1940 deaths {{Poland-mathematician-stub