Casimir energy of a two-dimensional conformal field theory (source code)

= Casimir energy of a two-dimensional conformal field theory
{title2=$E_0=-c/12$}

For a unit spatial circle, the vacuum energy of a two-dimensional conformal field theory is $E_0=-c/12$. It arises from the anomalous Schwarzian shift when the plane vacuum is mapped to the cylinder and is dual to the renormalized energy of global $\operatorname{AdS}_3$.