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Paul Halmos

 
Paul Halmos

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Paul Halmos



 
 
Paul Richard Halmos (March 3 1916 — October 2 2006) was a Hungarian
Hungary

Hungary , officially in English the Republic of Hungary , is a landlocked country in the Carpathian Basin of Central Europe, bordered by Austria, Slovakia, Ukraine, Romania, Serbia, Croatia, and Slovenia....
-born Jewish American
United States

The United States of America is a Federal government constitutional republic comprising U.S. state and a federal district. The country is situated mostly in central North America, where its Contiguous United States and Washington, D.C., the Capital districts and territories, lie between the Pacific Ocean and Atlantic Oceans, Borders of the U...
 mathematician
Mathematician

A mathematician is a person whose primary area of study and/or research is the field of mathematics....
 who made fundamental advances in the areas of probability theory
Probability theory

Probability theory is the branch of mathematics concerned with analysis of Statistical randomness phenomena. The central objects of probability theory are random variables, stochastic processes, and event s: mathematical abstractions of determinism events or measured quantities that may either be single occurrences or evolve over time in an a...
, statistics
Statistics

Statistics is a Mathematics pertaining to the collection, analysis, interpretation or explanation, and presentation of data. It also provides tools for prediction and forecasting based on data....
, operator theory
Operator theory

In mathematics, operator theory is the branch of functional analysis which deals with bounded linear operators and their properties. It can be split crudely into two branches, although there is considerable overlap and interplay between them....
, ergodic theory
Ergodic theory

Ergodic theory is a branch of mathematics that studies dynamical systemswith an invariant measure and related problems. Its initial development was motivated by problems of statistical physics....
, functional analysis
Functional analysis

Functional analysis is the branch of mathematics, and specifically of mathematical analysis, concerned with the study of vector spaces and operators acting upon them....
 (in particular, Hilbert space
Hilbert space

The mathematics concept of a Hilbert space, named after David Hilbert, generalizes the notion of Euclidean space. It extends the methods of vector algebra from the two-dimensional plane and three-dimensional space to infinite-dimensional spaces....
s), and mathematical logic
Mathematical logic

Mathematical logic is a subfield of mathematics and logic with close connections to computer science and philosophical logic. The field includes the mathematical study of logic and the applications of formal logic to other areas of mathematics....
. He was also recognized as a great mathematical expositor.

os obtained his B.A.






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Quotations


The only way to learn mathematics is to do mathematics.

Hilbert Space Problem Book

A good stock of examples, as large as possible, is indispensable for a thorough understanding of any concept, and when I want to learn something new, I make it my first job to build one.






Encyclopedia


Paul Halmos
Paul Richard Halmos (March 3 1916 — October 2 2006) was a Hungarian
Hungary

Hungary , officially in English the Republic of Hungary , is a landlocked country in the Carpathian Basin of Central Europe, bordered by Austria, Slovakia, Ukraine, Romania, Serbia, Croatia, and Slovenia....
-born Jewish American
United States

The United States of America is a Federal government constitutional republic comprising U.S. state and a federal district. The country is situated mostly in central North America, where its Contiguous United States and Washington, D.C., the Capital districts and territories, lie between the Pacific Ocean and Atlantic Oceans, Borders of the U...
 mathematician
Mathematician

A mathematician is a person whose primary area of study and/or research is the field of mathematics....
 who made fundamental advances in the areas of probability theory
Probability theory

Probability theory is the branch of mathematics concerned with analysis of Statistical randomness phenomena. The central objects of probability theory are random variables, stochastic processes, and event s: mathematical abstractions of determinism events or measured quantities that may either be single occurrences or evolve over time in an a...
, statistics
Statistics

Statistics is a Mathematics pertaining to the collection, analysis, interpretation or explanation, and presentation of data. It also provides tools for prediction and forecasting based on data....
, operator theory
Operator theory

In mathematics, operator theory is the branch of functional analysis which deals with bounded linear operators and their properties. It can be split crudely into two branches, although there is considerable overlap and interplay between them....
, ergodic theory
Ergodic theory

Ergodic theory is a branch of mathematics that studies dynamical systemswith an invariant measure and related problems. Its initial development was motivated by problems of statistical physics....
, functional analysis
Functional analysis

Functional analysis is the branch of mathematics, and specifically of mathematical analysis, concerned with the study of vector spaces and operators acting upon them....
 (in particular, Hilbert space
Hilbert space

The mathematics concept of a Hilbert space, named after David Hilbert, generalizes the notion of Euclidean space. It extends the methods of vector algebra from the two-dimensional plane and three-dimensional space to infinite-dimensional spaces....
s), and mathematical logic
Mathematical logic

Mathematical logic is a subfield of mathematics and logic with close connections to computer science and philosophical logic. The field includes the mathematical study of logic and the applications of formal logic to other areas of mathematics....
. He was also recognized as a great mathematical expositor.

Career

Halmos obtained his B.A. from the University of Illinois
University of Illinois at Urbana-Champaign

The University of Illinois at Urbana-Champaign is a public university research university in the state of Illinois, United States. It is the oldest and largest campus in the University of Illinois system....
, majoring in philosophy and minoring in mathematics. He took only three years to obtain the degree, and was only 19 when he graduated. He then began a Ph.D. in philosophy, but after failing his masters' oral exams, shifted to mathematics, graduating in 1938. Joseph Doob supervised his dissertation, titled Invariants of Certain Stochastic Transformation: The Mathematical Theory of Gambling Systems. Shortly thereafter, Halmos left for the Institute for Advanced Study
Institute for Advanced Study

The Institute for Advanced Study, located in Princeton, New Jersey, United States, is a center for theoretical research. The Institute is perhaps best known as the academic home of Albert Einstein, John von Neumann, and Kurt G?del, after their immigration to the United States....
, lacking both job and grant money. Six months later, he was working under John von Neumann
John von Neumann

John von Neumann was a Hungarian American mathematician who made major contributions to a vast range of fields, including set theory, functional analysis, quantum mechanics, ergodic theory, continuous geometry, economics and game theory, computer science, numerical analysis, hydrodynamics , and statistics, as well as many other mathematical...
, which proved a decisive experience. While at the Institute, Halmos wrote his first book, Finite Dimensional Vector Spaces, which immediately established his reputation as a fine expositor of mathematics.

Halmos taught at Syracuse University
Syracuse University

Syracuse University is a private research university located in Syracuse, New York, New York. It was founded as a university in 1870, but its roots can be traced back to a seminary founded by the Methodist Episcopal Church in 1832 which eventually became Genesee College....
, the University of Chicago
University of Chicago

The University of Chicago is a private university located principally in the Hyde Park, Chicago neighborhood of Chicago. Although an older university by the same name existed prior to its founding, the modern University of Chicago credits its founding to the oil magnate John D....
 (1946-60), the University of Michigan
University of Michigan

The University of Michigan, Ann Arbor, Michigan is a public university research university located in the state of Michigan. It is the state's oldest university and the flagship campus of the University of Michigan, which also includes two regional campuses in University of Michigan-Flint and University of Michigan-Dearborn....
, the University of California at Santa Barbara (about 1977), the University of Hawaii
University of Hawaii

The University of Hawaii System, formally the University of Hawaii and popularly known as UH, is a public, co-educational college and university system that confers associate, bachelor, master, doctoral and post-doctoral degrees through three university campuses, seven community college campuses, an employment training center, th...
, and Indiana University
Indiana University

Indiana University, founded in 1820, is a nine-campus university system in the state of Indiana. The IU system includes the following campuses:...
. From his 1985 retirement from Indiana until his death, he was affiliated with the Mathematics department at Santa Clara University
Santa Clara University

Santa Clara University is a private, co-educational Jesuit-affiliated university located in Santa Clara, California, California. Chartered by the state of California and accredited by the Western Association of Schools and Colleges, it operates in collaboration with the Society of Jesus , whose members founded the school in 1851....
.

He was married in 1945, to Virginia of Los Gatos, California.

Accomplishments

In a series of papers reprinted in his 1962 Algebraic Logic, Halmos devised polyadic algebras, an algebraic version of first-order logic
First-order logic

First-order logic is a formal deductive system used in mathematics, philosophy, linguistics, and computer science. It goes by many names, including: first-order predicate calculus , the lower predicate calculus, the language of first-order logic or predicate logic....
 differing from the better known cylindric algebra
Cylindric algebra

The notion of cylindric algebra, invented by Alfred Tarski, arises naturally in the Algebraic logic of first-order logic. This is comparable to the role Boolean algebra s play for propositional logic....
s of Alfred Tarski
Alfred Tarski

Alfred Tarski was a Poles logician and mathematician. Educated in the Warsaw School of Mathematics and philosophy, he emigrated to the USA in 1939, and taught and did research in mathematics at the University of California, Berkeley, from 1942 until his death....
 and his students. An elementary version of polyadic algebra is described in monadic Boolean algebra
Monadic Boolean algebra

In abstract algebra, a monadic Boolean algebra is an algebraic structure with signature where ⟨A, ·, +, ', 0, 1⟩ is a Boolean algebra ....
.

In addition to his original contributions to mathematics, Halmos was an unusually clear and engaging expositor of university mathematics. This was so even though Halmos arrived in the USA at 13 years of age and never lost his Hungarian accent. He chaired the American Mathematical Society
American Mathematical Society

The American Mathematical Society is an association of professional mathematicians dedicated to the interests of mathematics research and scholarship, which it does with various publications and conferences as well as annual monetary awards and prizes to mathematicians....
 committee that wrote the AMS style guide for academic mathematics, published in 1973. In 1983, he received the AMS's Steele Prize for exposition. Some of his classics were:
  • How to read mathematics
  • How to write mathematics
  • How to speak mathematics.


In the American Scientist 56(4): 375-389, Halmos argued that mathematics is a creative art, and that mathematicians should be seen as artists, not number crunchers. He discussed the division of the field into mathology and mathophysics, further arguing that mathematicians and painters think and work in related ways.

Halmos's 1985 "automathography" I Want to Be a Mathematician is an outstanding account of what it was like to be an academic mathematician in 20th century America. He called the book “automathography” rather than “autobiography”, because its focus is almost entirely on his life as a mathematician, not his personal life. The book contains the following quote on Halmos' view of what doing mathematics means, and is a favourite of many teachers of mathematics:

In these memoirs, Halmos claims to have invented the "iff" notation for the words "if and only if
If and only if

If and only if, in logic and fields that rely on it such as mathematics and philosophy, is a biconditional logical connective between statements....
" and to have been the first to use the “tombstone”
Tombstone (typography)

The tombstone, halmos, or end of proof mark "" is used in mathematics to denote the end of a Mathematical proof, in place of the traditional abbreviation "QED" for the Latin phrase "Q.E.D." ....
 notation to signify the end of a proof
Q.E.D.

Q.E.D. is an abbreviation of the List of Latin phrases , which literally means "which was to be demonstrated". The phrase is written in its abbreviated form at the end of a mathematical proof or Philosophy Logical argument, to signify that the last statement deduced was the one to be demonstrated, so the proof is complete....
, and this is generally agreed to be the case. The tombstone symbol (Unicode
Unicode

Unicode is a computing industry standard allowing computers to consistently represent and manipulate Character expressed in most of the world's writing systems....
 U+220E) is sometimes called a halmos.

Books by Halmos

  • 1942. Finite-Dimensional Vector Spaces
    Vector space

    File:Vector addition ans scaling.pngA vector space is a mathematical structure formed by a collection of vectors: objects that may be Vector addition together and Scalar multiplication by numbers, called scalar s in this context....
    . Springer-Verlag.
  • 1950. Measure Theory. Springer Verlag.
  • 1951. Introduction to Hilbert Space
    Hilbert space

    The mathematics concept of a Hilbert space, named after David Hilbert, generalizes the notion of Euclidean space. It extends the methods of vector algebra from the two-dimensional plane and three-dimensional space to infinite-dimensional spaces....
     and the Theory of Spectral Multiplicity
    . Chelsea.
  • 1956. Lectures on Ergodic Theory
    Ergodic theory

    Ergodic theory is a branch of mathematics that studies dynamical systemswith an invariant measure and related problems. Its initial development was motivated by problems of statistical physics....
    . Chelsea.
  • 1960. Naive Set Theory
    Naive Set Theory (book)

    Naive Set Theory is a mathematics textbook by Paul Halmos originally published in 1960. This book is an undergraduate introduction to not-very-naive set theory which has lasted for decades....
    . Springer Verlag.
  • 1962. Algebraic Logic. Chelsea.
  • 1963. Lectures on Boolean Algebras. Van Nostrand.
  • 1967. A Hilbert Space
    Hilbert space

    The mathematics concept of a Hilbert space, named after David Hilbert, generalizes the notion of Euclidean space. It extends the methods of vector algebra from the two-dimensional plane and three-dimensional space to infinite-dimensional spaces....
     Problem Book
    . Springer-Verlag.
  • 1978 (with V. Sunder). Bounded Integral Operators
    Integral transform

    In mathematics, an integral transform is any list of transforms T of the following form:The input of this transform is a function f, and the output is another function TF....
     on L˛ Spaces
    . Springer Verlag
  • 1985. I Want to Be a Mathematician. Springer-Verlag.
  • 1987. I Have a Photographic Memory. Mathematical Association of America
    Mathematical Association of America

    The Mathematical Association of America is a professional society that focuses on mathematics accessible at the undergraduate level. Members include university, college, and high school teachers; graduate and undergraduate students; pure and applied mathematicians; computer scientists; statisticians; and many others in academia, government,...
    .
  • 1991. Problems for Mathematicians, Young and Old, Dolciani Mathematical Expositions, Mathematical Association of America
    Mathematical Association of America

    The Mathematical Association of America is a professional society that focuses on mathematics accessible at the undergraduate level. Members include university, college, and high school teachers; graduate and undergraduate students; pure and applied mathematicians; computer scientists; statisticians; and many others in academia, government,...
    .
  • 1996. Linear Algebra Problem Book, Dolciani Mathematical Expositions, Mathematical Association of America
    Mathematical Association of America

    The Mathematical Association of America is a professional society that focuses on mathematics accessible at the undergraduate level. Members include university, college, and high school teachers; graduate and undergraduate students; pure and applied mathematicians; computer scientists; statisticians; and many others in academia, government,...
    .
  • 1998 (with Steven Givant). Logic as Algebra, Dolciani Mathematical Expositions No. 21, Mathematical Association of America
    Mathematical Association of America

    The Mathematical Association of America is a professional society that focuses on mathematics accessible at the undergraduate level. Members include university, college, and high school teachers; graduate and undergraduate students; pure and applied mathematicians; computer scientists; statisticians; and many others in academia, government,...
    .


External links

  • , Mathematical Association of America
    Mathematical Association of America

    The Mathematical Association of America is a professional society that focuses on mathematics accessible at the undergraduate level. Members include university, college, and high school teachers; graduate and undergraduate students; pure and applied mathematicians; computer scientists; statisticians; and many others in academia, government,...
     (MAA)