Equation 11.43.126654DDDC658F

\begin{equation} \min _{p\in P_ a}\sum _ i\lambda _ i p_ i =\frac a{\sum _ i\lambda _ i^{-1}}=:d_ a(\lambda ),\qquad y_ i=\frac{\sqrt a}{\lambda _ i\sum _ k\lambda _ k^{-1}}, \end{equation}