Laurence Chisholm Young (14 July 1905 – 24 December 2000) was a British

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...

known for his contributions to

measure theory In mathematics, the concept of a measure is a generalization and formalization of geometrical measures (length, area, volume) and other common notions, such as magnitude (mathematics), magnitude, mass, and probability of events. These seemingl ...

, the

calculus of variations The calculus of variations (or variational calculus) is a field of mathematical analysis that uses variations, which are small changes in Function (mathematics), functions and functional (mathematics), functionals, to find maxima and minima of f ...

optimal control theory Mathematical optimization (alternatively spelled ''optimisation'') or mathematical programming is the selection of a best element, with regard to some criteria, from some set of available alternatives. It is generally divided into two subfiel ...

, and

potential theory In mathematics and mathematical physics, potential theory is the study of harmonic functions. The term "potential theory" was coined in 19th-century physics when it was realized that the two fundamental forces of nature known at the time, namely g ...

. He was the son of

William Henry Young William Henry Young FRS (London, 20 October 1863 – Lausanne, 7 July 1942) was an English mathematician. Young was educated at City of London School and Peterhouse, Cambridge. He worked on measure theory, Fourier series, differential calcu ...

and

Grace Chisholm Young Grace Chisholm Young (née Chisholm, 15 March 1868 – 29 March 1944) was an English mathematician. She was educated at Girton College, Cambridge, England and continued her studies at Göttingen University in Germany, where in 1895 she receiv ...

, both prominent mathematicians. He moved to the US in 1949 but never sought American citizenship. The concept of

Young measure In mathematical analysis, a Young measure is a parameterized measure (mathematics), measure that is associated with certain subsequences of a given bounded sequence of measurable functions. They are a quantification of the oscillation effect of th ...

is named after him: he also introduced the concept of the generalized curve and a concept of generalized surface which later evolved in the concept of

varifold In mathematics, a varifold is, loosely speaking, a measure-theoretic generalization of the concept of a differentiable manifold, by replacing differentiability requirements with those provided by rectifiable sets, while maintaining the general alg ...

. The Young integral also is named after him and has now been generalised in the theory of rough paths.

Life and academic career

Laurence Chisholm Young was born in

Göttingen Göttingen (, ; ; ) is a college town, university city in Lower Saxony, central Germany, the Capital (political), capital of Göttingen (district), the eponymous district. The River Leine runs through it. According to the 2022 German census, t ...

,. the fifth of the six children of

and

.. He held positions of Professor at the University of Cape Town, South Africa, and at the University of Wisconsin-Madison. He was also a chess grandmaster.Grace Chisholm Young at Biographies of Women Mathematicians
/ref>

Selected publications

Books

*, available from the

Internet archive The Internet Archive is an American 501(c)(3) organization, non-profit organization founded in 1996 by Brewster Kahle that runs a digital library website, archive.org. It provides free access to collections of digitized media including web ...

. *. *.

Papers

*. *, memoir presented by

Stanisław Saks Stanisław Saks (30 December 1897 – 23 November 1942) was a Polish mathematician and university tutor, a member of the Lwów School of Mathematics, known primarily for his membership in the Scottish Café circle, an extensive monograph on the t ...

at the session of 16 December 1937 of the Warsaw Society of Sciences and Letters. The free

PDF Portable document format (PDF), standardized as ISO 32000, is a file format developed by Adobe Inc., Adobe in 1992 to present documents, including text formatting and images, in a manner independent of application software, computer hardware, ...

copy is made available by th
RCIN –Digital Repository of the Scientifics Institutes
*. *. *. *. *. *. *. *.

Notes

References

Biographical and general references

* *, including a reply by L. C. Young himself (pages 109–112). *.

Scientific references

*. One of the most complete monographs on the theory of

s, strongly oriented to applications in continuum mechanics of fluids. *. A thorough scrutiny of

s and their various generalization is in Chapter 3 from the perspective of

convex compactification In mathematics, specifically in convex analysis, the convex compactification is a compactification which is simultaneously a convex subset in a locally convex space in functional analysis. The convex compactification can be used for relaxation ...

s. *. *. An extended version of with a list of Almgren's publications.

External links

*
Obituary on University of Wisconsin web site
* {{DEFAULTSORT:Young, Laurence Chisholm 20th-century British mathematicians Alumni of Trinity College, Cambridge Mathematical analysts Scientists from Göttingen 1905 births 2000 deaths Variational analysts British historians of mathematics Instituto Nacional de Matemática Pura e Aplicada researchers