Modular Invariance in Superstring on Calabi-Yau n-fold with A-D-E Singularity

Tohru Eguchi, Yuji Sugawara

We study the type II superstring theory on the background $\br^{d-1,1}\times X_n$, where $X_n$ is a Calabi-Yau $n$-fold ($2n+d=10$) with an isolated singularity, by making use of t…