here exists a se-quence of initial data that satisfy all the hypothesis of item (i) and suchthat in the limit the equality in (3) is achieved. In this limit, the radius,the charge and the total mass of this sequence tend to zero.

A standard computation using the Gauss equation shows that∂f∂t(0,t′) =ddt|Σ0|g(t)(t′) =−∫Σ0(R−Ric(ν,ν))dμ=−4πχ(Σ0)−∫Σ0(Ric(ν,ν) +|A|2)dμ,where all geometric quantities are computed with respect tog(t′).

A computation in coordinates shows that the Ricci tensor ofhis given byRich(X,X) =−(1V∆gV)h(X,X),Rich(X,Z) = 0,Rich(Y,Z) =Ricg(Y,Z)−1V(HessgV)(Y,Z)

The structure of the metrichnear the singular set clearly implies thatgeodesics realizing the distance between a point inNand a component of∂Mmeets∂Morthogonally. The proof of this fact is essentially the sameas the proof of the Gauss’ Lemma.