Dedekind eta function
= Dedekind eta function
{c}
{title2=$\eta(\tau)$}
{wiki}
The Dedekind eta function is
$$
\eta(\tau)=q^{1/24}\prod_{n=1}^{\infty}(1-q^n),
\qquad q=e^{2\pi i\tau}.
$$
It packages the oscillator contribution of a chiral free boson.