Tirukkannapuram Vijayaraghavan (; 30 November 1902 – 20 April 1955) was an Indian mathematician from the
Madras
Chennai, also known as Madras ( its official name until 1996), is the capital and largest city of Tamil Nadu, the southernmost state of India. It is located on the Coromandel Coast of the Bay of Bengal. According to the 2011 Indian ce ...
region. He worked with
G. H. Hardy
Godfrey Harold Hardy (7 February 1877 – 1 December 1947) was an English mathematician, known for his achievements in number theory and mathematical analysis. In biology, he is known for the Hardy–Weinberg principle, a basic principle of pop ...
when he went to
Oxford
Oxford () is a City status in the United Kingdom, cathedral city and non-metropolitan district in Oxfordshire, England, of which it is the county town.
The city is home to the University of Oxford, the List of oldest universities in continuou ...
in mid-1920s on
Pisot–Vijayaraghavan number
In mathematics, a Pisot–Vijayaraghavan number, also called simply a Pisot number or a PV number, is a real algebraic integer greater than 1, all of whose Galois conjugates are less than 1 in absolute value. These numbers were discovered by Axe ...
s. He was a fellow of
Indian Academy of Sciences
The Indian Academy of Sciences, Bangalore was founded by Indian Physicist and List of Nobel laureates, Nobel Laureate Chandrasekhara Venkata Raman, C. V. Raman, and was registered as a society on 27 April 1934. Inaugurated on 31 July 1934, it ...
elected in the year 1934. His father was a ''
pandit
A pandit (; ; also spelled pundit, pronounced ; abbreviated Pt. or Pdt.) is an individual with specialised knowledge or a teacher of any field of knowledge in Hinduism, particularly the Vedic scriptures, dharma, or Hindu philosophy; in colonial-e ...
''.
Vijayaraghavan was well versed in Sanskrit and Tamil. He was a close friend of
André Weil
André Weil (; ; 6 May 1906 – 6 August 1998) was a French mathematician, known for his foundational work in number theory and algebraic geometry. He was one of the most influential mathematicians of the twentieth century. His influence is du ...
. Weil hired him in 1930 despite his lack of diploma, and they served together in
Aligarh Muslim University
Aligarh Muslim University is a Collegiate university, collegiate, Central university (India), central, and Research university, research university located in Aligarh, Uttar Pradesh, India, which was originally established by Sir Syed Ahmad Kh ...
. While Weil was away in Europe,
Ross Masood planned to replace Weil's professorship with Vijayaraghavan, but Vijayaraghavan quit in protest and moved to the
University of Dhaka
The University of Dhaka (), also known as Dhaka University (DU), is a public university, public research university located in Dhaka, Bangladesh. Established in 1921, it is the oldest active university in the country.
The University of Dhaka w ...
.
Vijayaraghavan proved a special case of
Herschfeld's theorem on
nested radicals
In algebra, a nested radical is a radical expression (one containing a square root sign, cube root sign, etc.) that contains (nests) another radical expression. Examples include
\sqrt,
which arises in discussing the regular pentagon, and more com ...
:
[ Ramanujan, S. Collected Papers of Srinivasa Ramanujan (Ed. G. H. Hardy, P. V. S. Aiyar, and B. M. Wilson). Providence, RI: American Mathematical Society (2000), p. 348.] For
:
converges if and only if
:
where
denotes the
limit superior
In mathematics, the limit inferior and limit superior of a sequence can be thought of as limiting (that is, eventual and extreme) bounds on the sequence. They can be thought of in a similar fashion for a function (see limit of a function). For ...
.
References
External links
*
Academic staff of Aligarh Muslim University
20th-century Indian mathematicians
Fellows of the Indian Academy of Sciences
1902 births
1955 deaths
Scientists from Chennai
Expatriates from British India in the United Kingdom
{{India-mathematician-stub