π and the hypergeometric functions of complex argument

TextIn this article we derive some new identities concerning π, algebraic radicals and some special occurrences of the Gauss hypergeometric function 2F1 in the analytic continuation. All of them have been derived by tackling some elliptic or hyperelliptic known integral, and looking for another representation of it by means of hypergeometric functions like those of Gauss, Appell or Lauricella. In any case we have focused on integrand functions having at least one couple of complex-conjugate roots. Founding upon a special hyperelliptic reduction formula due to Hermite (1876) [6], π   is obtained as a ratio of a complete elliptic integral and the four-variable Lauricella function. Furthermore, starting with a certain binomial integral, we succeed in providing 2/3 as a ratio of a linear combination of complete elliptic integrals of the first and second kinds to the Appell hypergeometric function of two complex-conjugate arguments. Each of the formulae we found theoretically has been satisfactorily tested by means of Mathematica®.VideoFor a video summary of this paper, please click here or visit http://www.youtube.com/watch?v=rQqtVtAf-RQ.