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G. H. Hardy

 
G. H. Hardy

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G. H. Hardy



 
 
G. H. (Godfrey Harold) Hardy FRS (February 7, 1877 Cranleigh
Cranleigh

Cranleigh is a large village, proclaimed the Largest village in England, and is situated 8 miles south east of Godalming in Surrey. It lies to the east of the A281 which links Guildford with Horsham; neighbouring villages include: Ewhurst, Surrey, Alfold and Hascombe....
, Surrey
Surrey

Surrey is a counties of England in the South East England of England and is one of the Home Counties. The county borders Greater London, Kent, East Sussex, West Sussex, Hampshire, and Berkshire....
, England
England

native_name =|conventional_long_name = England|common_name = England|image_flag = Flag of England.svg|image_coat = England COA.svg|symbol_type = Royal Coat of Arms...
  – December 1, 1947 Cambridge
Cambridge

The city status in the United Kingdom of Cambridge is a College town and the administrative centre of the county of Cambridgeshire, England. It lies about 50 miles north of London....
, Cambridgeshire
Cambridgeshire

Cambridgeshire is a Counties_of_the_United_Kingdom#England in England, bordering Lincolnshire to the north, Norfolk to the northeast, Suffolk to the east, Essex, England and Hertfordshire to the south, and Bedfordshire and Northamptonshire to the west....
, England ) was a prominent English
England

native_name =|conventional_long_name = England|common_name = England|image_flag = Flag of England.svg|image_coat = England COA.svg|symbol_type = Royal Coat of Arms...
 mathematician
Mathematics

Mathematics is the study of quantity, structure, space, change, and related topics of pattern and form. Mathematicians seek out patterns whether found in numbers, space, natural science, computers, imaginary abstractions, or elsewhere....
, known for his achievements in number theory
Number theory

Number theory is the branch of pure mathematics concerned with the properties of numbers in general, and integers in particular, as well as the wider classes of problems that arise from their study....
 and mathematical analysis
Mathematical analysis

Mathematical analysis, which mathematicians refer to simply as analysis, has its beginnings in the rigorous formulation of calculus. It is the branch of mathematics most explicitly concerned with the notion of a limit , whether the limit of a sequence or the limit of a function....
.

Non-mathematicians usually know him for A Mathematician's Apology
A Mathematician's Apology

A Mathematician's Apology is a 1940 essay by British mathematician G. H. Hardy. It concerns the aesthetics of mathematics with some personal content, and gives the layman an insight into the mind of a working mathematician....
, his essay
Essay

An essay is usually a short piece of writing. It is often written from an author's personal Perspective . Essays can be literary criticism, political manifestos, learned arguments, observations of daily life, recollections, and reflections of the author....
 from 1940 on the aesthetics of mathematics. The apology is often considered one of the best insights into the mind of a working mathematician written for the layman
Layman

The term "layman" originated from the use of the term laity, but over the centuries, changed definition to mean a person who is a non-expert in a given field of knowledge....
.

His relationship as mentor, from 1914 onwards, of the Indian mathematician Srinivasa Ramanujan
Srinivasa Ramanujan

Srinivasa Ramanujan Ivengar Fellow of the Royal Society, better known as Srinivasa Ramanujan was an Indian mathematician, who, with almost no formal training in pure mathematics, made substantial contributions to mathematical analysis, number theory, infinite series and continued fractions....
 has become celebrated.






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Quotations


Beauty is the first test: there is no permanent place in the world for ugly mathematics.

I am interested in mathematics only as a creative art.

No discovery of mine has made, or is likely to make, for good or ill, the least difference to the amenity of the world.

There is no scorn more profound, or on the whole more justifiable, than that of the men who make for the men who explain. Exposition, criticism, appreciation, is work for second-rate minds.

A mathematician, like a painter or poet, is a maker of patterns. If his patterns are more permanent than theirs, it is because they are made with ideas.

Archimedes will be remembered when Aeschylus is forgotten, because languages die and mathematical ideas do not. Immortality may be a silly word, but probably a mathematician has the best chance of whatever it may mean.






Encyclopedia


G. H. (Godfrey Harold) Hardy FRS (February 7, 1877 Cranleigh
Cranleigh

Cranleigh is a large village, proclaimed the Largest village in England, and is situated 8 miles south east of Godalming in Surrey. It lies to the east of the A281 which links Guildford with Horsham; neighbouring villages include: Ewhurst, Surrey, Alfold and Hascombe....
, Surrey
Surrey

Surrey is a counties of England in the South East England of England and is one of the Home Counties. The county borders Greater London, Kent, East Sussex, West Sussex, Hampshire, and Berkshire....
, England
England

native_name =|conventional_long_name = England|common_name = England|image_flag = Flag of England.svg|image_coat = England COA.svg|symbol_type = Royal Coat of Arms...
  – December 1, 1947 Cambridge
Cambridge

The city status in the United Kingdom of Cambridge is a College town and the administrative centre of the county of Cambridgeshire, England. It lies about 50 miles north of London....
, Cambridgeshire
Cambridgeshire

Cambridgeshire is a Counties_of_the_United_Kingdom#England in England, bordering Lincolnshire to the north, Norfolk to the northeast, Suffolk to the east, Essex, England and Hertfordshire to the south, and Bedfordshire and Northamptonshire to the west....
, England ) was a prominent English
England

native_name =|conventional_long_name = England|common_name = England|image_flag = Flag of England.svg|image_coat = England COA.svg|symbol_type = Royal Coat of Arms...
 mathematician
Mathematics

Mathematics is the study of quantity, structure, space, change, and related topics of pattern and form. Mathematicians seek out patterns whether found in numbers, space, natural science, computers, imaginary abstractions, or elsewhere....
, known for his achievements in number theory
Number theory

Number theory is the branch of pure mathematics concerned with the properties of numbers in general, and integers in particular, as well as the wider classes of problems that arise from their study....
 and mathematical analysis
Mathematical analysis

Mathematical analysis, which mathematicians refer to simply as analysis, has its beginnings in the rigorous formulation of calculus. It is the branch of mathematics most explicitly concerned with the notion of a limit , whether the limit of a sequence or the limit of a function....
.

Non-mathematicians usually know him for A Mathematician's Apology
A Mathematician's Apology

A Mathematician's Apology is a 1940 essay by British mathematician G. H. Hardy. It concerns the aesthetics of mathematics with some personal content, and gives the layman an insight into the mind of a working mathematician....
, his essay
Essay

An essay is usually a short piece of writing. It is often written from an author's personal Perspective . Essays can be literary criticism, political manifestos, learned arguments, observations of daily life, recollections, and reflections of the author....
 from 1940 on the aesthetics of mathematics. The apology is often considered one of the best insights into the mind of a working mathematician written for the layman
Layman

The term "layman" originated from the use of the term laity, but over the centuries, changed definition to mean a person who is a non-expert in a given field of knowledge....
.

His relationship as mentor, from 1914 onwards, of the Indian mathematician Srinivasa Ramanujan
Srinivasa Ramanujan

Srinivasa Ramanujan Ivengar Fellow of the Royal Society, better known as Srinivasa Ramanujan was an Indian mathematician, who, with almost no formal training in pure mathematics, made substantial contributions to mathematical analysis, number theory, infinite series and continued fractions....
 has become celebrated. Hardy almost immediately recognized Ramanujan's extraordinary albeit untutored brilliance, and Hardy and Ramanujan became close collaborators. In an interview by Paul Erdos
Paul Erdos

Paul Erdos was an immensely prolific and famously eccentric Hungary mathematician. With hundreds of collaborators, he worked on problems in combinatorics, graph theory, number theory, classical analysis, approximation theory, set theory, and probability theory....
, when Hardy was asked what his greatest contribution to mathematics was, Hardy unhesitatingly replied that it was the discovery of Ramanujan. He called their collaboration "the one romantic incident in my life."

Life


G.H. Hardy was born 7 February 1877, in Cranleigh
Cranleigh

Cranleigh is a large village, proclaimed the Largest village in England, and is situated 8 miles south east of Godalming in Surrey. It lies to the east of the A281 which links Guildford with Horsham; neighbouring villages include: Ewhurst, Surrey, Alfold and Hascombe....
, Surrey
Surrey

Surrey is a counties of England in the South East England of England and is one of the Home Counties. The county borders Greater London, Kent, East Sussex, West Sussex, Hampshire, and Berkshire....
, England
England

native_name =|conventional_long_name = England|common_name = England|image_flag = Flag of England.svg|image_coat = England COA.svg|symbol_type = Royal Coat of Arms...
, into a teaching family. His father was Bursar
Bursar

A Bursar is a senior professional finance academic administration in a school or university. According to the bursar's website at San Jose State University, ?Bursar is a term unique to higher education and means a Business Officer, or Custodian of University Funds....
 and Art Master at Cranleigh School
Cranleigh School

Cranleigh School is an independent England boarding school in the village of Cranleigh, Surrey. It was founded in 1865 as a boys' school and started to admit girls in the early 1970s....
; his mother had been a senior mistress at Lincoln Training College for teachers. Both parents were mathematically inclined.

Hardy's own natural affinity for mathematics was perceptible at a young age. When just two years old, he wrote numbers up to millions, and when taken to church he amused himself by factorizing the numbers of the hymns.

After schooling at Cranleigh
Cranleigh School

Cranleigh School is an independent England boarding school in the village of Cranleigh, Surrey. It was founded in 1865 as a boys' school and started to admit girls in the early 1970s....
, Hardy was awarded a scholarship to Winchester College
Winchester College

Winchester College is a famous boys' independent school, set in the city of Winchester, Hampshire in Hampshire, England, once the ancient capital....
 for his mathematical work. In 1896 he entered Trinity College
Trinity College, Cambridge

Trinity College is one of the 31 Colleges of the University of Cambridge of the University of Cambridge. Trinity has more members than any other college in Cambridge or University of Oxford, with around 700 undergraduates, 430 graduate students, and over 160 Fellows; however, counting only the student body it has somewhat fewer than Homert...
, Cambridge
University of Cambridge

The University of Cambridge , located in Cambridge, England, is the List of oldest universities in continuous operation university in the Anglosphere....
. After only two years of preparation he was fourth in the Mathematics Tripos
Cambridge Mathematical Tripos

The Mathematical Tripos is the taught mathematics course at the University of Cambridge. It is the oldest Tripos that is examined in Cambridge....
 examination. Years later, Hardy sought to abolish the Tripos system, as he felt that it was becoming more an end in itself than a means to an end. While at university, Hardy joined the Cambridge Apostles
Cambridge Apostles

The Cambridge Apostles, also known as the Cambridge Conversazione Society, is an intellectual secret society at the University of Cambridge founded in 1820 by George Tomlinson, a Cambridge student who went on to become the first Bishop of Gibraltar in Europe....
, an elite, intellectual secret society.

As the most important influence Hardy cites the self-study of Cours d'analyse de l'École Polytechnique by the French mathematician Camille Jordan
Camille Jordan

Marie Ennemond Camille Jordan was a France mathematician, known both for his foundational work in group theory and for his influential Cours d'analyse....
, through which he became acquainted with the more precise mathematics tradition in continental Europe
Europe

Europe is, conventionally, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally divided from Asia to its east by the water divide of the Ural Mountains, the Ural , the Caspian Sea, and by the Caucasus Mountains to the southeast....
. In 1900 he passed part II of the tripos and was awarded a fellowship. In 1903 he earned his M.A., which was the highest academic degree at English universities at that time. From 1906 onward he held the position of a lecturer, who had to teach six hours per week leaving him plenty of time for research. In 1919 he left Cambridge to take the Savilian Chair of Geometry
Savilian Chair of Geometry

The Savilian Chair of Geometry is the position of professor of mathematics at the University of Oxford in England. The holder is now a member of the University's The Mathematical Institute, University of Oxford....
 at Oxford in the aftermath of the Bertrand Russell affair
Bertrand Russell

Bertrand Arthur William Russell, 3rd Earl Russell, Order of Merit , Fellow of the Royal Society , was a British people philosopher, mathematical logic, mathematician, historian, advocate for social reform, and pacifism....
 during World War I
World War I

World War I, or the First World War , was a global military conflict which involved the Great powers, organized into two opposing military alliances: the Allies of World War I and the Central Powers....
. He returned to Cambridge in 1931, where he was Sadleirian Professor until 1942.

The Indian Clerk (2007) is a novel by David Leavitt
David Leavitt

David Leavitt is an United States novelist....
 based on Hardy's life at Cambridge
Cambridge

The city status in the United Kingdom of Cambridge is a College town and the administrative centre of the county of Cambridgeshire, England. It lies about 50 miles north of London....
, including his discovery of and relationship with Srinivasa Ramanujan
Srinivasa Ramanujan

Srinivasa Ramanujan Ivengar Fellow of the Royal Society, better known as Srinivasa Ramanujan was an Indian mathematician, who, with almost no formal training in pure mathematics, made substantial contributions to mathematical analysis, number theory, infinite series and continued fractions....
.

Work


Hardy is credited with reforming British mathematics by bringing rigour
Rigour

Rigour or rigor has a number of meanings in relation to intellectual life and discourse. These are separate from public and political applications with their suggestion of laws enforced to the letter, or political absolutism....
 into it, which was previously a characteristic of French
France

France , officially the French Republic , is a country whose Metropolitan France is located in Western Europe and that also comprises various Overseas departments and territories of France....
, Swiss
Switzerland

Switzerland is a landlocked Swiss Alps country of roughly 7.7 million people in Western Europe with an area of 41,285 km?. Switzerland is a federal republic consisting of 26 states called Cantons of Switzerland....
 and German
Germany

Germany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium, and the Netherlands....
 mathematics. British mathematicians had remained largely in the tradition of applied mathematics
Applied mathematics

Applied mathematics is a branch of mathematics that concerns itself with the mathematical techniques typically used in the application of mathematical knowledge to other domains....
, in thrall to the reputation of Isaac Newton
Isaac Newton

Sir Isaac Newton, Fellow of the Royal Society was an English people physicist, mathematician, Astronomy, Natural philosophy, Alchemy, and Theology and one of the the 100 in human history....
 (see Cambridge Mathematical Tripos
Cambridge Mathematical Tripos

The Mathematical Tripos is the taught mathematics course at the University of Cambridge. It is the oldest Tripos that is examined in Cambridge....
). Hardy was more in tune with the cours d'analyse methods dominant in France, and aggressively promoted his conception of pure mathematics
Pure mathematics

Broadly speaking, pure mathematics is mathematics motivated entirely for reasons other than application. It is distinguished by its Rigour#Mathematical_rigour, abstraction and mathematical beauty....
, in particular against the hydrodynamics which was an important part of Cambridge mathematics.

From 1911 he collaborated with J. E. Littlewood, in extensive work in mathematical analysis
Mathematical analysis

Mathematical analysis, which mathematicians refer to simply as analysis, has its beginnings in the rigorous formulation of calculus. It is the branch of mathematics most explicitly concerned with the notion of a limit , whether the limit of a sequence or the limit of a function....
 and analytic number theory
Analytic number theory

In mathematics, analytic number theory is a branch of number theory that uses methods from mathematical analysis to solve number-theoretical problems....
. This (along with much else) led to quantitative progress on the Waring problem, as part of the Hardy-Littlewood circle method
Hardy-Littlewood circle method

In mathematics, the Hardy?Littlewood circle method is one of the most frequently used techniques of analytic number theory. It is named for G. H....
, as it became known. In prime number
Prime number

In mathematics, a prime number is a natural number which has exactly two distinct natural number divisors: 1 and itself. An infinitude of prime numbers exists, as demonstrated by Euclid around 300 BC....
 theory, they proved results and some notable conditional results. This was a major factor in the development of number theory as a system of conjecture
Conjecture

In mathematics, a conjecture is a mathematical statement which appears resourceful, but has not been formally proven to be true under the rules of mathematical logic....
s; examples are the first and second Hardy-Littlewood conjecture
Second Hardy-Littlewood conjecture

In number theory, the second Hardy-Littlewood conjecture concerns the number of prime number in intervals. If π is the number of primes up to and including x then the conjecture states that...
s. Hardy's collaboration with Littlewood is among the most successful and famous collaborations in mathematical history. In a 1947 lecture, the Danish mathematician Harald Bohr
Harald Bohr

Harald August Bohr was a Denmark mathematician and Football player. As a student, his footballing skill meant he was called up to the Denmark national football team for the 1908 Summer Olympics, where he won a silver medal....
 said, "To illustrate to what extent Hardy and Littlewood in the course of the years came to be considered as the leaders of recent English mathematical research, I may report what an excellent colleague once jokingly said: 'Nowadays, there are only three really great English mathematicians: Hardy, Littlewood, and Hardy-Littlewood.'"

Hardy is also known for formulating the Hardy-Weinberg principle
Hardy-Weinberg principle

The Hardy?Weinberg principle states that both allele and genotype frequencies in a population remain constant—that is, they are in equilibrium—from generation to generation unless specific disturbing influences are introduced....
, a basic principle of population genetics
Population genetics

Population genetics is the study of the allele frequency distribution and change under the influence of the four evolutionary processes: natural selection, genetic drift, mutation and gene flow....
, independently from Wilhelm Weinberg
Wilhelm Weinberg

Dr Wilhelm Weinberg was a Germany physician who in 1908 independently of the British mathematician G.H. Hardy, formulated the Hardy-Weinberg principle....
 in 1908. He played cricket
Cricket

Cricket is a Bat-and-ball games team sport that originated in southern England. The earliest definite reference is dated 1598, and it is now played in more than 100 countries....
 with the geneticist Reginald Punnett
Reginald Punnett

Professor Reginald Crundall Punnett Fellow of the Royal Society was a United Kingdom genetics who co-founded, with William Bateson, the Journal of Genetics in 1910....
 who introduced the problem to him, and Hardy thus became the somewhat unwitting founder of a branch of applied mathematics.

His collected papers have been published in seven volumes by Oxford University Press.

Pure mathematics

Hardy preferred his work to be considered pure mathematics
Pure mathematics

Broadly speaking, pure mathematics is mathematics motivated entirely for reasons other than application. It is distinguished by its Rigour#Mathematical_rigour, abstraction and mathematical beauty....
, perhaps because of his detestation of war and the military uses to which mathematics had been applied
Applied mathematics

Applied mathematics is a branch of mathematics that concerns itself with the mathematical techniques typically used in the application of mathematical knowledge to other domains....
. He made several statements similar to that in his Apology
A Mathematician's Apology

A Mathematician's Apology is a 1940 essay by British mathematician G. H. Hardy. It concerns the aesthetics of mathematics with some personal content, and gives the layman an insight into the mind of a working mathematician....
:
"I have never done anything 'useful'. No discovery of mine has made, or is likely to make, directly or indirectly, for good or ill, the least difference to the amenity of the world."
However, aside from formulating the Hardy-Weinberg principle in population genetics
Population genetics

Population genetics is the study of the allele frequency distribution and change under the influence of the four evolutionary processes: natural selection, genetic drift, mutation and gene flow....
, his famous work on integer partitions with his collaborator Ramanujan, known as the Hardy-Ramanujan asymptotic formula, has been widely applied in physics to find quantum partition functions of atomic nuclei (first used by Niels Bohr) and to derive thermodynamic functions of non-interacting Bose-Einstein systems. Though Hardy wanted his maths to be "pure" and devoid of any application, much of his work has found applications in other branches of science.

Moreover, Hardy deliberately pointed out in his Apology that mathematicians generally do not "glory in the uselessness of their work," but rather – because science can be used for evil as well as good ends – "mathematicians may be justified in rejoicing that there is one science at any rate, and that their own, whose very remoteness from ordinary human activities should keep it gentle and clean." Hardy also rejected as a "delusion" the belief that the difference between pure and applied mathematics had anything to do with their utility. Hardy regards as "pure" the kinds of mathematics that are independent of the physical world, but also considers some "applied" mathematicians, such as the physicists Maxwell
James Clerk Maxwell

James Clerk Maxwell was a Scotland Mathematical physics. His most significant achievement was the development of the classical electromagnetic theory, synthesizing all previous unrelated observations, experiments and equations of electricity, magnetism and even optics into a consistent theory....
 and Einstein
Albert Einstein

Albert Einstein was a Germany-born theoretical physics. He is best known for his theory of relativity and specifically mass?energy equivalence, expressed by the equation E = mc2....
, to be among the "real" mathematicians, whose work "has permanent aesthetic value" and "is eternal because the best of it may, like the best literature, continue to cause intense emotional satisfaction to thousands of people after thousands of years." Although he admitted that what he called "real" mathematics may someday become useful, he asserted that, at the time in which the Apology was written, only the "dull and elementary parts" of either pure or applied mathematics could "work for good or ill."

Attitudes and personality


Socially he was associated with the Bloomsbury group
Bloomsbury Group

The Bloomsbury Group was an England collectivity of friends and relatives who lived in or near London during the first half of the twentieth century....
 and the Cambridge Apostles
Cambridge Apostles

The Cambridge Apostles, also known as the Cambridge Conversazione Society, is an intellectual secret society at the University of Cambridge founded in 1820 by George Tomlinson, a Cambridge student who went on to become the first Bishop of Gibraltar in Europe....
; G. E. Moore, Bertrand Russell
Bertrand Russell

Bertrand Arthur William Russell, 3rd Earl Russell, Order of Merit , Fellow of the Royal Society , was a British people philosopher, mathematical logic, mathematician, historian, advocate for social reform, and pacifism....
 and J. M. Keynes were friends. He was an avid cricket fan and befriended the young C. P. Snow
C. P. Snow

Charles Percy Snow, Baron Snow Order of the British Empire was an England physicist and novelist, who also served several important positions in the Government of the United Kingdom....
 who was one also.

He was at times politically involved, if not an activist. He took part in the Union of Democratic Control
Union of Democratic Control

The Union of Democratic Control was a United Kingdom pressure group formed in 1914 to press for a more responsive foreign policy. While not a pacifism organization, it was opposed to military influence in government....
 during World War I, and For Intellectual Liberty in the late 1930s.

Hardy was an atheist
Atheism

Atheism is the absence or rejection of belief in deity, or the explicit view that Existence of God.Many list of atheists are Skepticism of all supernatural beings and cite a lack of empiricism evidence for the existence of deities....
. He was a life-long bachelor, and in his final years he was cared for by his sister.

Hardy was extremely shy as a child, and was socially awkward, cold and eccentric throughout his life. During his school years he was top of his class in most subjects, and won many prizes and awards but hated having to receive them in front of the entire school. He was uncomfortable being introduced to new people, and could not bear to look at his own reflection in a mirror. It is said that, when staying in hotels, he would cover all the mirrors with towels.

In his , a former student reports: "He was an extremely kind-hearted man, who could not bear any of his pupils to fail in their researches." — E. C. Titchmarsh (1950)

Hardy’s aphorisms

  • It is never worth a first class man's time to express a majority opinion. By definition, there are plenty of others to do that.
  • A mathematician, like a painter or a poet, is a maker of patterns. If his patterns are more permanent than theirs, it is because they are made with ideas.
  • Nothing I have ever done is of the slightest practical use.


Books

  • Hardy G. H. (1940) A Mathematician's Apology
    A Mathematician's Apology

    A Mathematician's Apology is a 1940 essay by British mathematician G. H. Hardy. It concerns the aesthetics of mathematics with some personal content, and gives the layman an insight into the mind of a working mathematician....
    , Cambridge University Press; Reprint edition (January 31, 1992). ISBN 0-521-42706-1.
  • Hardy G. H. (1940) Ramanujan, Cambridge University Press: London (1940). Ams Chelsea Pub. (November 25, 1999) ISBN 0-8218-2023-0.
  • Hardy G. H. (1908) A Course of Pure Mathematics
    A Course of Pure Mathematics

    A Course of Pure Mathematics is a classic textbook in introductory mathematical analysis, written by G. H. Hardy. It was first published in 1908, and went through many editions....
    , Cambridge University Press; 10th edition (June 25, 1993). ISBN 0-521-09227-2. Available at archive.org.*

See also

  • Hardy notation
    Hardy notation

    In complexity theory and mathematics, the Hardy notation, introduced by G. H. Hardy, is used for asymptotic comparison of functions, equivalently to Landau notation ....
  • Hardy space
    Hardy space

    In complex analysis, the Hardy spaces Hp are certain spaces of Holomorphic function on the unit disk or upper half plane. They were introduced by Frigyes Riesz , who named them after G....
  • Pisot-Vijayaraghavan number
    Pisot-Vijayaraghavan number

    In mathematics, a Pisot-Vijayaraghavan number, also called simply a Pisot number or a PV number, is an algebraic integer α which is real and exceeds 1, but such that its conjugate elements are all less than 1 in absolute value or modulus....
  • Hardy's inequality
    Hardy's inequality

    Hardy's inequality is an inequality in mathematics, named after G. H. Hardy. It states that if is a sequence of non-negative real numbers which is not identically zero, then for every real number p > 1 one has...


External links

  • *I. Grattan-Guinness, ""