Tirukkannapuram Vijayaraghavan

Thirukannapuram Vijayaraghavan
Born	30 November 1902
Died	April 20, 1955 (aged 52)
Occupation	mathematician

Tirukkannapuram Vijayaraghavan (Tamil: திருக்கண்ணபுரம் விஜயராகவன்; 30 November 1902 – 20 April 1955) was an Indian mathematician from the Madras region. He worked with G. H. Hardy when he went to Oxford in mid-1920s on Pisot–Vijayaraghavan numbers. He was a fellow of Indian Academy of Sciences elected in the year 1934.

Vijayaraghavan was well versed in Sanskrit and Tamil. He was a close friend of André Weil. He served with him in Aligarh Muslim University. He later shifted to University of Dhaka, protesting Weil's firing from AMU.^[1]

Vijayaraghavan proved a special case of Herschfeld's theorem on nested radicals:^[2] For $a_n>0$

$\sqrt{a_1 + \sqrt{a_2 + \sqrt{a_3 + \sqrt{a_4 + \cdots}}}}$

converges if and only if

$\overline{\lim} (\log a_n)/2^n < +\infty,$

where $\overline{\lim}$ denotes the limit superior.

References

1. M.S. Raghunathan, Artless innocents and ivory-tower sophisticates: Some personalities on the Indian mathematical scene.
2. 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.

External links

• Tirukkannapuram Vijayaraghavan at the Mathematics Genealogy Project