New explicit formulas for Faltings' delta-invariant

In this paper we give new explicit formulas for Faltings' $\delta$-invariant in terms of integrals of theta functions, and we deduce an explicit lower bound for $\delta$ only in terms of the genus and an explicit upper bound for the Arakelov-Green function in terms of $\delta$. Furthermore, we give a canonical extension of $\delta$ and the Zhang-Kawazumi invariant $\varphi$ to the moduli space of indecomposable principally polarised complex abelian varieties.