Equation 12.4.388A03DC67E97

\[\begin{aligned}\begin{align} -\frac{\mathrm{d}^2}{\mathrm{d}t^2}\log \lambda _\mu (\theta _ t) & =\frac1n\int _ X\operatorname {tr}(A_\chi ^2)\, \mathrm{d}\nu _\Omega . \end{align}\end{aligned}\]