Carl Ludwig Siegel
Carl Ludwig Siegel ( 31 December 1896 – 4 April 1981 ) was a German mathematician specialising in analytic number theory . 
<triplet> Carl Ludwig Siegel <subj> 31 December 1896 <obj> date of birth <subj> 4 April 1981 <obj> date of death <subj> German <obj> country of citizenship