Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.
DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.
We give a criterion for a nef divisor D to be semi-ample on a Calabi-Yau threefold X when D3 = 0 = c2 (X)center dot D and c3 (X) 6= 0. As a direct consequence, we show that on such a variety X, if D is strictly nef and.(D) 6= 1, then D is ample; we also show that if there exists a Cariter divisor D 6= 0 in the boundary of the nef cone of X, then X contains a rational curve when its topological Euler characteristic is not 0