André Bloch (mathematician)
Encyclopedia
André Bloch was a Jewish-French
mathematician
who is best remembered for a result called Bloch's theorem
. Bloch was institutionalized
in a mental asylum for thirty-one years of his life, during which all of his mathematical output was produced.
, France
. According to one of his teachers, Georges Valiron
, both André Bloch and his younger brother Georges were the same class in October 1910. Valiron believed Georges to have the better talent, and due to lack of preparation, André finished last in the class. André was spared from failing the class by convincing Ernest Vessiot
to give him an oral exam. The exam convinced Vessiot of Andre's talent and both André and Georges entered the Ecole Polytechnique
.
Both brothers served for a year in the military prior to World War I
. Both André and Georges studied for only one year at the Ecole Polytechnique
before the outbreak of the war.
in 1914, André and Georges Bloch were drafted. André, as a second-lieutenant in the artillery, was assigned to the headquarters of General De Castelnau
in Nancy.
Both Bloch brothers were injured: André suffered from a fall from an observation post, while Georges sustained a head wound which cost him an eye . Georges was released from service and returned to the Ecole Polytechnique on 7 October 1917. André, however, was allowed to convalesce but not released from duty.
, Bloch killed his brother Georges,
and his aunt and uncle. Several motives are given by mathematicians for Bloch's crime. However, Cartan and Ferrand quote Henri Baruk
, who was the medical head of the asylum where Bloch was confined. Bloch told Baruk that the murders
were a eugenic
act, in order to eliminate branches of his family affected by mental illness.
in Saint Maurice
, a suburb of Paris
. Bloch continued his mathematical career while confined. All of his publications, including those relating to Bloch's constant, were written while he was committed. Bloch corresponded with several
mathematicians, including Georges Valiron
, George Pólya
, Jacques Hadamard
and others, giving his return address as only "57 Grande rue, Saint-Maurice", never mentioning that this was a psychiatric hospital. Several of his correspondents were thus unaware of his situation.
During the German occupation of France during World War II, Bloch (who was Jewish) wrote under aliases
,
in order to avoid advertising his presence to Nazi occupiers. In particular, Bloch is known to have authored papers under the
names of René Binaud and Marcel Segond during this time.
According to Pólya
, Bloch had the habit of dating his letters with 1 April, regardless of when they were written.
Bloch was transferred to the Saint Anne's Hospital in Paris on 21 August 1948 for an operation. He died from leukemia
in Paris on 11 October 1948.
. This result defines a numerical value which is referred to as "Bloch's constant". While Bloch provided in 1925 estimates of this constant (namely, that it was at least 1/72 ), to date, the exact value of Bloch's constant is unknown.
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
mathematician
Mathematician
A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....
who is best remembered for a result called Bloch's theorem
Bloch's theorem (complex variables)
In complex analysis, a field within mathematics, Bloch's theorem is a result that gives a lower bound on the size of the image of a certain class of holomorphic functions. It is named after André Bloch.-Statement:...
. Bloch was institutionalized
Institutionalized
Institutionalized may refer to:* The act of being placed in a psychiatric hospital* "Institutionalized" , a song on Suicidal Tendencies 1983 titular album* Institutionalized , a 2005 rap album by American rapper Ras Kass...
in a mental asylum for thirty-one years of his life, during which all of his mathematical output was produced.
Early life
Bloch was born in 1893 in BesançonBesançon
Besançon , is the capital and principal city of the Franche-Comté region in eastern France. It had a population of about 237,000 inhabitants in the metropolitan area in 2008...
, France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
. According to one of his teachers, Georges Valiron
Georges Valiron
Georges Jean Marie Valiron was a French mathematician, notable for his contributions to analysis, in particular, the asymptotic behaviour of entire functions of finite order and Tauberian theorems....
, both André Bloch and his younger brother Georges were the same class in October 1910. Valiron believed Georges to have the better talent, and due to lack of preparation, André finished last in the class. André was spared from failing the class by convincing Ernest Vessiot
Ernest Vessiot
Ernest Vessiot was a French mathematician. He was born in Marseille, France and died in La Bauche, Savoie, France...
to give him an oral exam. The exam convinced Vessiot of Andre's talent and both André and Georges entered the Ecole Polytechnique
École Polytechnique
The École Polytechnique is a state-run institution of higher education and research in Palaiseau, Essonne, France, near Paris. Polytechnique is renowned for its four year undergraduate/graduate Master's program...
.
Both brothers served for a year in the military prior to World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
. Both André and Georges studied for only one year at the Ecole Polytechnique
École Polytechnique
The École Polytechnique is a state-run institution of higher education and research in Palaiseau, Essonne, France, near Paris. Polytechnique is renowned for its four year undergraduate/graduate Master's program...
before the outbreak of the war.
World War I
Upon the outbreak of World War IWorld War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
in 1914, André and Georges Bloch were drafted. André, as a second-lieutenant in the artillery, was assigned to the headquarters of General De Castelnau
Noël Édouard, vicomte de Curières de Castelnau
Noël Marie Joseph Édouard, Vicomte de Curières de Castelnau was a French general in World War I, one of the leading proponents of the philosophy of attaque à outrance that dominated French military thinking in the early part of the war.Born in Gascony to a family with a long history of military...
in Nancy.
Both Bloch brothers were injured: André suffered from a fall from an observation post, while Georges sustained a head wound which cost him an eye . Georges was released from service and returned to the Ecole Polytechnique on 7 October 1917. André, however, was allowed to convalesce but not released from duty.
Murder
On 17 November 1917, while on convalescent leave from service in World War IWorld War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
, Bloch killed his brother Georges,
and his aunt and uncle. Several motives are given by mathematicians for Bloch's crime. However, Cartan and Ferrand quote Henri Baruk
Henri Baruk
Henri Baruk was a French neuropsychiatrist of Jewish descent, an apostle of moral psychiatry, whose studies have been used to advance concepts such as Marxism and other liberal movements of the 1960s.-Biography:Baruk spent his childhood among patients at the Lesvellec's Asylum where his father,...
, who was the medical head of the asylum where Bloch was confined. Bloch told Baruk that the murders
were a eugenic
Eugenics
Eugenics is the "applied science or the bio-social movement which advocates the use of practices aimed at improving the genetic composition of a population", usually referring to human populations. The origins of the concept of eugenics began with certain interpretations of Mendelian inheritance,...
act, in order to eliminate branches of his family affected by mental illness.
Commitment and mathematical career
After the murders, Bloch was committed to the asylum at CharentonCharenton (asylum)
Charenton was a lunatic asylum, founded in 1645 by the Frères de la Charité in Charenton-Saint-Maurice, now Saint-Maurice, Val-de-Marne, France....
in Saint Maurice
Saint-Maurice, Val-de-Marne
Saint-Maurice is a commune in the southeastern suburbs of Paris, France. It is located from the center of Paris. The insane asylum Charenton was located in Saint-Maurice; it is now a psychiatric hospital.-History:...
, a suburb of Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...
. Bloch continued his mathematical career while confined. All of his publications, including those relating to Bloch's constant, were written while he was committed. Bloch corresponded with several
mathematicians, including Georges Valiron
Georges Valiron
Georges Jean Marie Valiron was a French mathematician, notable for his contributions to analysis, in particular, the asymptotic behaviour of entire functions of finite order and Tauberian theorems....
, George Pólya
George Pólya
George Pólya was a Hungarian mathematician. He was a professor of mathematics from 1914 to 1940 at ETH Zürich and from 1940 to 1953 at Stanford University. He made fundamental contributions to combinatorics, number theory, numerical analysis and probability theory...
, Jacques Hadamard
Jacques Hadamard
Jacques Salomon Hadamard FRS was a French mathematician who made major contributions in number theory, complex function theory, differential geometry and partial differential equations.-Biography:...
and others, giving his return address as only "57 Grande rue, Saint-Maurice", never mentioning that this was a psychiatric hospital. Several of his correspondents were thus unaware of his situation.
During the German occupation of France during World War II, Bloch (who was Jewish) wrote under aliases
Pseudonym
A pseudonym is a name that a person assumes for a particular purpose and that differs from his or her original orthonym...
,
in order to avoid advertising his presence to Nazi occupiers. In particular, Bloch is known to have authored papers under the
names of René Binaud and Marcel Segond during this time.
According to Pólya
George Pólya
George Pólya was a Hungarian mathematician. He was a professor of mathematics from 1914 to 1940 at ETH Zürich and from 1940 to 1953 at Stanford University. He made fundamental contributions to combinatorics, number theory, numerical analysis and probability theory...
, Bloch had the habit of dating his letters with 1 April, regardless of when they were written.
Bloch was transferred to the Saint Anne's Hospital in Paris on 21 August 1948 for an operation. He died from leukemia
Leukemia
Leukemia or leukaemia is a type of cancer of the blood or bone marrow characterized by an abnormal increase of immature white blood cells called "blasts". Leukemia is a broad term covering a spectrum of diseases...
in Paris on 11 October 1948.
Bloch's theorem
Bloch is the namesake of Bloch's theoremBloch's theorem (complex variables)
In complex analysis, a field within mathematics, Bloch's theorem is a result that gives a lower bound on the size of the image of a certain class of holomorphic functions. It is named after André Bloch.-Statement:...
. This result defines a numerical value which is referred to as "Bloch's constant". While Bloch provided in 1925 estimates of this constant (namely, that it was at least 1/72 ), to date, the exact value of Bloch's constant is unknown.
External links
- Bloch's Constant at PlanetMathPlanetMathPlanetMath is a free, collaborative, online mathematics encyclopedia. The emphasis is on rigour, openness, pedagogy, real-time content, interlinked content, and also community of about 24,000 people with various maths interests. Intended to be comprehensive, the project is hosted by the Digital...
- Bloch's Theorem at PlanetMathPlanetMathPlanetMath is a free, collaborative, online mathematics encyclopedia. The emphasis is on rigour, openness, pedagogy, real-time content, interlinked content, and also community of about 24,000 people with various maths interests. Intended to be comprehensive, the project is hosted by the Digital...