Radha Laha

{{EngvarB|date=September 2014}} {{Use dmy dates|date=September 2014}} {{Infobox scientist |name = Laha, Radha |birth_name = Radha Govind Laha |birth_date = 1 October 1930 |birth_place = Calcutta, India |death_date = {{d-da|14 July 1999|1 October 1930}} |death_place = Perrysburg, Ohio |fields = Mathematician, Probabilist, Statistician |workplaces = Indian Statistical Institute, Calcutta <br /> Catholic University of America <br /> Bowling Green State University |alma_mater = Indian Statistical Institute, Calcutta University |doctoral_advisor = C. R. Rao |known_for = Work in Characteristic Functions, Probability Theory }}

'''Radha Govind Laha''' (1 October 1930 – 14 July 1999) was an Indian-American probabilist, statistician, and mathematician, known for his work in probability theory,<ref name=LR79>{{Cite book|author=R. G. Laha and V. K. Rohatgi|year=1979|pages=557|title=Probability Theory|publisher=Wiley|location=New York.}}</ref> characteristic functions,<ref name=LL1>{{Cite book |author=E. Lukacs and R. G. Laha|title=Applications of Characteristic Functions (Griffin's Statistical Monographs & Courses, No. 14)|location=New York|publisher=T. Hafner Pub. Co.|year=1964 |pages=202}}</ref> and characterisation of distributions.<ref name=LLN60>Laha, Lukacs, and Newman (1960)</ref><ref name=Laha>Laha (1957,1958a,1958b,1959,1991,1998)</ref><ref name=LL2>Laha and Lukacs (1960,1962,1977)</ref> ==Biography== ===Early life=== He was born in Calcutta, India and he was a student of C. R. Rao<ref name=MathG>{{MathGenealogy|id=48987}}</ref> at Calcutta University, where in 1957 he earned a doctorate in analytical probability theory from the Indian Statistical Institute. His dissertation was entitled ''On Characterization of probability distribution and statistics from specified scholastic relations''.

Laha's primary and secondary education was completed in Calcutta. In 1949 he graduated first in rank with a bachelor's degree in statistics from Presidency College, Calcutta.<ref name=LahaBio>{{cite web| url = http://www.maths.uq.edu.au/MASCOS/misc/Laha.pdf |title= Professor Radha Govind Laha| access-date = 1 March 2011}}</ref> He earned his master's degree in statistics in 1951, and doctoral degree in analytical probability theory from Calcutta University in 1957.<ref name=LahaBio/> Prizes and awards during this period include the Saradprasad prize, the Duff scholarship, the S.S. Bose Gold Medal, University of Calcutta Silver Medal, and Fulbright Fellowship in the US.<ref name=LahaBio/>

===Career=== In 1952 Laha joined the staff of the Indian Statistical Institute, Theoretical Research and Training School, Calcutta, India, in pure and applied statistics. In 1958 he was a research associate at Catholic University of America in Washington, D.C. He returned to the Indian Statistical Institute for two years, and joined the faculty of Catholic University as a faculty member in 1962. During this period Laha established an international reputation, and he visited statistical institutes at University of Paris, France, ETH Zurich, Switzerland, and in the United States. He moved to Bowling Green State University in 1972, along with his colleagues Eugene Lukacs and Vijay Rohatgi, to start a new PhD program there.<ref>For an announcement see {{cite web| title=International Mathematical News | date = May 1972 | url=http://www.oemg.ac.at/IMN/imn101.pdf |page=22|access-date = 4 March 2011}}</ref> Laha retired from Bowling Green State University in 1996 and died in Perrysburg, Ohio on 14 July 1999 after a long illness.<ref name=Laha-bio2>{{cite web|url = http://www.bgsu.edu/departments/math/faculty/page52758.html| title = Radha Laha (biographical sketch)|access-date = 4 March 2011}}</ref>

Laha was the author of several classical texts on probability theory<ref name=LR79/><ref name=LL1/> and statistics<ref>{{Cite book|author=I. M. Chakrevarti, R. G. Laha and J. Roy|year=1967|title=Handbook of Methods of Applied Statistics I: Techniques of computation, descriptive methods, and statistical inference|publisher=Wiley|location=New York.}}</ref><ref>{{Cite book|author=I. M. Chakrevarti, R. G. Laha and J. Roy|year=1967|title=Handbook of Methods of Applied Statistics II: Planning of surveys and experiments|publisher=Wiley|location=New York.}}</ref> and numerous publications in journals. He was an honoured Fellow of the Institute of Mathematical Statistics<ref>{{cite web | url= http://www.imstat.org/awards/honored_fellows.htm | title= Honored IMS Fellows | access-date= 1 March 2011 | archive-date= 2 March 2014 | archive-url= https://web.archive.org/web/20140302125855/http://www.imstat.org/awards/honored_fellows.htm | url-status= dead }}</ref> and an elected member of the International Statistical Institute.

Laha was particularly interested in characterisations of the normal distribution.<ref name=Laha-bio2 /><ref>Radha G. Laha (obituary), The Toledo Blade, 18 July 1999.</ref> One of his well-known results is his disproof of a long-standing conjecture: that the ratio of two independent, identically distributed random variables is Cauchy distributed if and only if the variables have normal distributions. Laha became known for disproving this conjecture.<ref>{{cite journal|journal = Proceedings of the National Academy of Sciences | author = R. G. Laha | year = 1958 | volume = 44 | pages = 222–223 | title = An Example of a Nonnormal Distribution where the Quotient Follows the Cauchy Law| url = http://www.pnas.org/content/44/2/222.full.pdf | issue=2|doi = 10.1073/pnas.44.2.222| pmc = 335393 | pmid=16590171| bibcode = 1958PNAS...44..222L | doi-access = free }}</ref> Laha also proved several generalisations of the classical characterisation of normal sample distribution by the independence of sample mean and sample variance.<ref>Laha (1991)</ref> ===Philanthropist=== Laha made a generous endowment from his estate to the American Mathematical Society<ref>{{cite web|url= https://www.ams.org/about-us/governance/board/ecbt-minutes-0501.pdf |title = Minutes, American Mathematical Society Executive Committee and Board of Trustees, May 18–19, 2001, Providence, Rhode Island: Minutes, Item 3.6 ''Bequest from the Estate of Radha G. Laha''|access-date=26 February 2011}}</ref> and the Institute of Mathematical Statistics. The AMS established the Radha G. Laha Gardens in 2001.<ref>[https://www.ams.org/about-us/support-ams/laha-gardens AMS Dedicates Radha G. Laha Gardens]</ref> A portion of the Laha Gardens outside the AMS headquarters<ref>[https://www.ams.org/about-us/about-us American Mathematical Society]</ref> in Providence, Rhode Island is identified by a plaque inscribed 'to honour his gift and commitment to mathematical research'. In 2001 with Laha's generous bequest, the Institute of Mathematical Statistics established the Laha Awards<ref>[http://www.imstat.org/awards/laha.html IMS Laha Travel Award] {{webarchive|url=https://web.archive.org/web/20101212195001/http://imstat.org/awards/laha.html |date=12 December 2010 }}</ref> to provide travel funds to present a paper at the IMS Annual Meeting.

==Notes== {{Reflist}}

== Books ==

* {{Cite book |author=E. Lukacs and R. G. Laha|title=Applications of Characteristic Functions (Griffin's Statistical Monographs & Courses, No. 14)|location=New York|publisher=T. Hafner Pub. Co.|year=1964 |pages=202}} * {{Cite book|author=I. M. Chakrevarti, R. G. Laha and J. Roy|year=1967|title=Handbook of Methods of Applied Statistics I: Techniques of computation, descriptive methods, and statistical inference|publisher=Wiley|location=New York.}} * {{Cite book|author=I. M. Chakrevarti, R. G. Laha and J. Roy|year=1967|title=Handbook of Methods of Applied Statistics II: Planning of surveys and experiments|publisher=Wiley|location=New York.}} * {{Cite book|author=R. G. Laha and V. K. Rohatgi|year=1979|pages=557|title=Probability Theory|publisher=Wiley|location=New York.}}

== Journal articles ==

* {{cite journal | last1 = Kagan | first1 = Abram | last2 = Laha | first2 = R. G. | year = 2001 | title = A property of linear forms of independent random variables related to uniqueness of linear structure | journal = J. Statist. Plann. Inference | volume = 92 | issue = 1–2| pages = 13–20 | doi = 10.1016/S0378-3758(00)00159-2 }} * {{cite journal | last1 = Laha | first1 = R. G. | year = 1998 | title = An extension of the Darmois–Skitovich theorem | journal = Math. Methods Statist | volume = 7 | issue = 4| pages = 479–483 }} * {{cite journal | last1 = Kagan | first1 = A. | last2 = Laha | first2 = R. G. | last3 = Rohatgi | first3 = V. |name-list-style=vanc | year = 1997 | title = Independence of the sum and absolute difference of independent random variables does not imply their normality | journal = Math. Methods Statist | volume = 6 | issue = 2| pages = 263–265 }} * Laha, R. G. (1991). A characterisation of Gaussian law in Hilbert space, ''Aequationes Mathematicae'' 41 (1991), no. 1, 85–93. * {{cite journal | last1 = Laha | first1 = R. G. | last2 = Lukacs | first2 = E. | year = 1977 | title = On a functional equation which occurs in a characterization problem | journal = Aequationes Mathematicae | volume = 16 | issue = 3| pages = 259–274 | doi = 10.1007/BF01836038 | s2cid = 122866588 }} * {{cite journal | last1 = Laha | first1 = R. G. | year = 1964 | title = On the decomposition of a class of functions of bounded variation | journal = Can. J. Math. | volume = 16 | pages = 479–484 | doi = 10.4153/CJM-1964-049-8 | s2cid = 124766763 | doi-access = free }} * {{cite journal | last1 = Laha | first1 = R. G. | last2 = Lukacs | first2 = E. | year = 1962 | title = On a factorization of characteristic functions which have a finite number of derivatives at the origin | journal = Publ. Inst. Statist. Univ. Paris | volume = 11 | pages = 221–224 }} * {{cite journal | last1 = Laha | first1 = R. G. | last2 = Lukacs | first2 = E. | year = 1964 | title = On a problem connected with quadratic regression | journal = Biometrika | volume = 47 | issue = 3–4| pages = 335–343 | doi=10.1093/biomet/47.3-4.335}} * {{cite journal | last1 = Laha | first1 = R. G. | last2 = Lukacs | first2 = E. | last3 = Newman | first3 = M. | year = 1960 | title = On the independence of a sample central moment and the sample mean | journal = Annals of Mathematical Statistics | volume = 31 | issue = 4| pages = 1028–1033 | doi = 10.1214/aoms/1177705675 | doi-access = free }} * {{cite journal | last1 = Laha | first1 = R. G. | last2 = Lukacs | first2 = E. | year = 1960 | title = On certain functions of normal variates which are uncorrelated of a higher order | journal = Biometrika | volume = 47 | issue = 1–2| pages = 175–176 | doi=10.1093/biomet/47.1-2.175}} * {{cite journal | last1 = Laha | first1 = R. G. | year = 1959 | title = On the laws of Cauchy and Gauss | journal = Annals of Mathematical Statistics | volume = 30 | issue = 4| pages = 1165–1174 | doi = 10.1214/aoms/1177706102 | doi-access = free }} * {{cite journal | last1 = Laha | first1 = R. G. | year = 1958a | title = On a factorization theorem in the theory of analytic characteristic functions | journal = Annals of Mathematical Statistics | volume = 29 | issue = 3| pages = 922–926 | doi = 10.1214/aoms/1177706553 | doi-access = free }} * {{cite journal | last1 = Laha | first1 = R. G. | year = 1958b | title = An example of a nonnormal distribution where the quotient follows the Cauchy law | journal = Proc. Natl. Acad. Sci. USA | volume = 44 | issue = 2| pages = 222–223 | doi = 10.1073/pnas.44.2.222 | pmc = 335393 | pmid=16590171| bibcode = 1958PNAS...44..222L | doi-access = free }} * {{cite journal | last1 = Roy | first1 = J. | last2 = Laha | first2 = R. G. | year = 1957 | title = On partially balanced linked block designs | journal = Annals of Mathematical Statistics | volume = 28 | issue = 2| pages = 488–493 | doi = 10.1214/aoms/1177706977 | doi-access = free }} * {{cite journal | last1 = Laha | first1 = R. G. | year = 1957 | title = On some characterization problems connected with linear structural relations | journal = Annals of Mathematical Statistics | volume = 28 | issue = 2| pages = 405–414 | doi = 10.1214/aoms/1177706968 | doi-access = free }} * {{cite journal|last1=Basu | first1=D. |last2 = Laha | first2 = R. G.| title= On Some Characterizations of the Normal Distribution| journal=Sankhyā | volume=13| issue=4| year=1954| pages = 359–362| jstor=25048183}}

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{{DEFAULTSORT:Laha, Radha}} Category:1930 births Category:1999 deaths Category:20th-century Indian mathematicians Category:Probability theorists Category:Indian statisticians Category:University of Calcutta alumni Category:Catholic University of America faculty Category:Fellows of the Institute of Mathematical Statistics Category:Academic staff of the Indian Statistical Institute Category:Scientists from Kolkata Category:20th-century American statisticians