Tirukkannapuram Vijayaraghavan

Tirukkannapuram Vijayaraghavan (Tamil: திருக்கண்ணபுரம் விஜயராகவன்; 30 November 1902 – 20 April 1955) was an Indian mathematician from 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.

Vijayaraghavan proved a special case of Herschfeld's theorem on nested radicals: 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.

External links

• Tirukkannapuram Vijayaraghavan at the Mathematics Genealogy Project