Counting Unimodular Lattices in ${\mathbb{R}}^{r,s}$

Shinobu Hosono, Bong H. Lian, Keiji Oguiso +1

Narain lattices are unimodular lattices {\it in} ${\mathbb{R}}^{r,s}$, subject to certain natural equivalence relation and rationality condition. The problem of describing and counting these…