Integrated density of states for the Poisson point interactions on ${\mathbf{R}}^3$

We determine the principal term of the asymptotics of the integrated density of states (IDS) $N(\lambda )$ for the Schrödinger operator with point interactions on ${\mathbf{R}}^3$ as $\lambda \to -\mathrm{\infty }$, provided that the set of positions of the point obstacles is the Poisson configuration, and the interaction parameters are bounded i.i.d.\ random variables. In particular, we prove $N(\lambda )=O(\mathrm{\mid }\lambda {\mathrm{\mid }}^{-3\mathrm{/}2})$ as $\lambda \to -\mathrm{\infty }$. In the case that all interaction parameters are equal to a constant, we give a more detailed asymptotics of $N(\lambda )$, and verify the result by a numerical method using R.