As a natural generalization of the Euler's constant $\gamma$, Y. Ihara introduced the Euler-Kronecker constants attached to any number field. In this talk, we will discuss the connection between these constants and certain arithmetic properties of number fields.
Euler's
remarkable formula for $\zeta(2m)$ immediately tells us that even zeta
values are transcendental. However, the algebraic nature of odd zeta
values is yet to be determined. Page 320 and 332 of Ramanujan's
Lost Notebook contains an intriguing identity for $\zeta(2m+1)$ and
$\zeta(1/2)$, respectively. Many mathematicians have studied these
identities over the years.
In
this talk, we shall discuss transformation formulas for a certain
infinite series, which will enable us to derive Ramanujan's formula for
$\zeta(1/2),$ Wigert's formula for $\zeta(1/k)$, as well as Ramanujan's
formula for $\zeta(2m+1)$. We also obtain a new identity for
$\zeta(-1/2)$ in the spirit of Ramanujan.