Mahlon Marsh Day (1913–1992) was an American mathematician, who specialized in

functional analysis Functional analysis is a branch of mathematical analysis, the core of which is formed by the study of vector spaces endowed with some kind of limit-related structure (e.g. Inner product space#Definition, inner product, Norm (mathematics)#Defini ...

, geometry of linear spaces and amenable

semigroup In mathematics, a semigroup is an algebraic structure consisting of a set together with an associative internal binary operation on it. The binary operation of a semigroup is most often denoted multiplicatively: ''x''·''y'', or simply ''xy'', ...

Career

In 1939 he graduated from

Brown University Brown University is a private research university in Providence, Rhode Island. Brown is the seventh-oldest institution of higher education in the United States, founded in 1764 as the College in the English Colony of Rhode Island and Providenc ...

. He became a member of the

Institute for Advanced Study The Institute for Advanced Study (IAS), located in Princeton, New Jersey, in the United States, is an independent center for theoretical research and intellectual inquiry. It has served as the academic home of internationally preeminent scholar ...

in the years 1939-40 and later in 1948–49. In most of his career, between the years 1940–83, he was a professor of mathematics in

University of Illinois at Urbana-Champaign The University of Illinois Urbana-Champaign (U of I, Illinois, University of Illinois, or UIUC) is a public land-grant research university in Illinois in the twin cities of Champaign and Urbana. It is the flagship institution of the Univ ...

. In June 1983, a conference named "the Geometry of Normed Linear Spaces" was held in honor of Day at the

. A proceedings issue to the conference was published in

Contemporary Mathematics Contemporary history, in English-language historiography, is a subset of modern history that describes the historical period from approximately 1945 to the present. Contemporary history is either a subset of the late modern period, or it is o ...

. In the preface for this proceedings issue, Day was described as "the first American mathematician to study normed spaces from a geometric standpoint". His monograph "Normed Linear Spaces" from 1973 is highly cited and considered to be classical in the field. In the field of amenable semigroups, his work under this name, is highly cited and considered fundamental to the field. He served as an editor of

Illinois Journal of Mathematics The ''Illinois Journal of Mathematics'' is a quarterly peer-reviewed scientific journal of mathematics published by Duke University Press on behalf of the University of Illinois. It was established in 1957 by Reinhold Baer, Joseph L. Doob, Abraha ...

in the years 1968-73 and 1981–85.

Selected publications

* Day, M. M. (1957). Amenable semigroups. Illinois Journal of Mathematics, 1(4), 509-544. * Day, M. M. (1973). Normed linear spaces. In Normed Linear Spaces (pp. 27–52). Springer, Berlin, Heidelberg. * R. G. Bartle, N. T. Peck, A. L. Peressini, J. J. Uhl (Editors)
Geometry of Normed Linear Spaces
Contemporary Mathematics. Volume: 52; 1986; 171 pp
Book front matter

References

External links

Mahlon M. Day Papers, 1934-93
University of Illinois Archives
Profile at Institute for Advanced Study
* {{Cite web, url=https://www.ias.edu/scholars/mahlon-marsh-day, title=Mahlon Marsh Day, website=Institute for Advanced Study, language=en American mathematicians 1913 births 1992 deaths Brown University alumni University of Illinois faculty